1
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Posmyk K, Zawadzka N, Łucja Kipczak, Dyksik M, Surrente A, Maude DK, Kazimierczuk T, Babiński A, Molas MR, Bumrungsan W, Chooseng C, Paritmongkol W, Tisdale WA, Baranowski M, Plochocka P. Bright Excitonic Fine Structure in Metal-Halide Perovskites: From Two-Dimensional to Bulk. J Am Chem Soc 2024; 146:4687-4694. [PMID: 38324275 PMCID: PMC10885139 DOI: 10.1021/jacs.3c11957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
The optical response of two-dimensional (2D) perovskites, often referred to as natural quantum wells, is primarily governed by excitons, whose properties can be readily tuned by adjusting the perovskite layer thickness. We have investigated the exciton fine structure splitting in the archetypal 2D perovskite (PEA)2(MA)n-1PbnI3n+1 with varying numbers of inorganic octahedral layers n = 1, 2, 3, and 4. We demonstrate that the in-plane excitonic states exhibit splitting and orthogonally oriented dipoles for all confinement regimes. The evolution of the exciton states in an external magnetic field provides further insights into the g-factors and diamagnetic coefficients. With increasing n, we observe a gradual evolution of the excitonic parameters characteristic of a 2D to three-dimensional transition. Our results provide valuable information concerning the evolution of the optoelectronic properties of 2D perovskites with the changing confinement strength.
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Affiliation(s)
- Katarzyna Posmyk
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw 50-370, Poland
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Grenoble Alpes, Université Toulouse, Université Toulouse 3, INSA-T, 38042 Grenoble, Toulouse 31400, France
| | - Natalia Zawadzka
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - Łucja Kipczak
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - Mateusz Dyksik
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw 50-370, Poland
| | - Alessandro Surrente
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw 50-370, Poland
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Grenoble Alpes, Université Toulouse, Université Toulouse 3, INSA-T, 38042 Grenoble, Toulouse 31400, France
| | - Tomasz Kazimierczuk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - Adam Babiński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - Maciej R Molas
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - Wakul Bumrungsan
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Chanisara Chooseng
- Department of Chemical and Biomolecular Engineering, School of Energy Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Watcharaphol Paritmongkol
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - William A Tisdale
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michał Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw 50-370, Poland
| | - Paulina Plochocka
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw 50-370, Poland
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Grenoble Alpes, Université Toulouse, Université Toulouse 3, INSA-T, 38042 Grenoble, Toulouse 31400, France
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2
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Dyksik M, Beret D, Baranowski M, Duim H, Moyano S, Posmyk K, Mlayah A, Adjokatse S, Maude DK, Loi MA, Puech P, Plochocka P. Polaron Vibronic Progression Shapes the Optical Response of 2D Perovskites. Adv Sci (Weinh) 2024; 11:e2305182. [PMID: 38072637 PMCID: PMC10870061 DOI: 10.1002/advs.202305182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/23/2023] [Indexed: 02/17/2024]
Abstract
The optical response of 2D layered perovskites is composed of multiple equally-spaced spectral features, often interpreted as phonon replicas, separated by an energy Δ ≃ 12 - 40 meV, depending upon the compound. Here the authors show that the characteristic energy spacing, seen in both absorption and emission, is correlated with a substantial scattering response above ≃ 200 cm-1 (≃ 25 meV) observed in resonant Raman. This peculiar high-frequency signal, which dominates both Stokes and anti-Stokes regions of the scattering spectra, possesses the characteristic spectral fingerprints of polarons. Notably, its spectral position is shifted away from the Rayleigh line, with a tail on the high energy side. The internal structure of the polaron consists of a series of equidistant signals separated by 25-32 cm-1 (3-4 meV), depending upon the compound, forming a polaron vibronic progression. The observed progression is characterized by a large Huang-Rhys factor (S > 6) for all of the 2D layered perovskites investigated here, indicative of a strong charge carrier - lattice coupling. The polaron binding energy spans a range ≃ 20-35 meV, which is corroborated by the temperature-dependent Raman scattering data. The investigation provides a complete understanding of the optical response of 2D layered perovskites via the direct observation of polaron vibronic progression. The understanding of polaronic effects in perovskites is essential, as it directly influences the suitability of these materials for future opto-electronic applications.
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Affiliation(s)
- Mateusz Dyksik
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
| | - Dorian Beret
- CEMES‐UPR8011CNRSUniversity of Toulouse29 rue Jeanne MarvigToulouse31500France
| | - Michal Baranowski
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
| | - Herman Duim
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Sébastien Moyano
- CEMES‐UPR8011CNRSUniversity of Toulouse29 rue Jeanne MarvigToulouse31500France
| | - Katarzyna Posmyk
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
- Laboratoire National des Champs Magnétiques IntensesEMFL, CNRS UPR 3228University Toulouse, University Toulouse 3, INSA‐T, University Grenoble AlpesGrenoble and ToulouseFrance
| | - Adnen Mlayah
- LAASUniversity of ToulouseCNRS, UPS, 7 Avenue du Colonel RocheToulouse31031France
| | - Sampson Adjokatse
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Duncan K. Maude
- Laboratoire National des Champs Magnétiques IntensesEMFL, CNRS UPR 3228University Toulouse, University Toulouse 3, INSA‐T, University Grenoble AlpesGrenoble and ToulouseFrance
| | - Maria Antonietta Loi
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Pascal Puech
- CEMES‐UPR8011CNRSUniversity of Toulouse29 rue Jeanne MarvigToulouse31500France
| | - Paulina Plochocka
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
- Laboratoire National des Champs Magnétiques IntensesEMFL, CNRS UPR 3228University Toulouse, University Toulouse 3, INSA‐T, University Grenoble AlpesGrenoble and ToulouseFrance
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3
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Yang Z, Fauqué B, Nomura T, Shitaokoshi T, Kim S, Chowdhury D, Pribulová Z, Kačmarčík J, Pourret A, Knebel G, Aoki D, Klein T, Maude DK, Marcenat C, Kohama Y. Unveiling the double-peak structure of quantum oscillations in the specific heat. Nat Commun 2023; 14:7006. [PMID: 37938579 PMCID: PMC10632398 DOI: 10.1038/s41467-023-42730-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 10/16/2023] [Indexed: 11/09/2023] Open
Abstract
Quantum oscillation phenomenon is an essential tool to understand the electronic structure of quantum matter. Here we report a systematic study of quantum oscillations in the electronic specific heat Cel in natural graphite. We show that the crossing of a single spin Landau level and the Fermi energy give rise to a double-peak structure, in striking contrast to the single peak expected from Lifshitz-Kosevich theory. Intriguingly, the double-peak structure is predicted by the kernel term for Cel/T in the free electron theory. The Cel/T represents a spectroscopic tuning fork of width 4.8kBT which can be tuned at will to resonance. Using a coincidence method, the double-peak structure can be used to accurately determine the Landé g-factors of quantum materials. More generally, the tuning fork can be used to reveal any peak in fermionic density of states tuned by magnetic field, such as Lifshitz transition in heavy-fermion compounds.
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Affiliation(s)
- Zhuo Yang
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
| | - Benoît Fauqué
- JEIP, USR 3573 CNRS, Collège de France, PSL Research University, 11, Place Marcelin Berthelot, 75231, Paris Cedex 05, France
| | - Toshihiro Nomura
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Takashi Shitaokoshi
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Sunghoon Kim
- Department of Physics, Cornell University, Ithaca, NY, 14853, USA
| | | | - Zuzana Pribulová
- Centre of Low Temperature Physics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, SK-04001, Košice, Slovakia
| | - Jozef Kačmarčík
- Centre of Low Temperature Physics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, SK-04001, Košice, Slovakia
| | - Alexandre Pourret
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 38000, Grenoble, France
| | - Georg Knebel
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 38000, Grenoble, France
| | - Dai Aoki
- Institute for Materials Research, Tohoku University, Oarai, Ibaraki, 311-1313, Japan
| | - Thierry Klein
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400, Toulouse, France
| | - Christophe Marcenat
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 38000, Grenoble, France
| | - Yoshimitsu Kohama
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
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4
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Palai SK, Dyksik M, Sokolowski N, Ciorga M, Sánchez Viso E, Xie Y, Schubert A, Taniguchi T, Watanabe K, Maude DK, Surrente A, Baranowski M, Castellanos-Gomez A, Munuera C, Plochocka P. Approaching the Intrinsic Properties of Moiré Structures Using Atomic Force Microscopy Ironing. Nano Lett 2023. [PMID: 37276177 DOI: 10.1021/acs.nanolett.2c04765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Stacking monolayers of transition metal dichalcogenides (TMDs) has led to the discovery of a plethora of new exotic phenomena, resulting from moiré pattern formation. Due to the atomic thickness and high surface-to-volume ratio of heterostructures, the interfaces play a crucial role. Fluctuations in the interlayer distance affect interlayer coupling and moiré effects. Therefore, to access the intrinsic properties of the TMD stack, it is essential to obtain a clean and uniform interface between the layers. Here, we show that this is achieved by ironing with the tip of an atomic force microscope. This post-stacking procedure dramatically improves the homogeneity of the interfaces, which is reflected in the optical response of the interlayer exciton. We demonstrate that ironing improves the layer coupling, enhancing moiré effects and reducing disorder. This is crucial for the investigation of TMD heterostructure physics, which currently suffers from low reproducibility.
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Affiliation(s)
- Swaroop Kumar Palai
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| | - Mateusz Dyksik
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Nikodem Sokolowski
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| | - Mariusz Ciorga
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Estrella Sánchez Viso
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Yong Xie
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Alina Schubert
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| | - Alessandro Surrente
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Michał Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Andres Castellanos-Gomez
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Carmen Munuera
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
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5
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Wang S, Dyksik M, Lampe C, Gramlich M, Maude DK, Baranowski M, Urban AS, Plochocka P, Surrente A. Thickness-Dependent Dark-Bright Exciton Splitting and Phonon Bottleneck in CsPbBr 3-Based Nanoplatelets Revealed via Magneto-Optical Spectroscopy. Nano Lett 2022; 22:7011-7019. [PMID: 36036573 PMCID: PMC9479212 DOI: 10.1021/acs.nanolett.2c01826] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The optimized exploitation of perovskite nanocrystals and nanoplatelets as highly efficient light sources requires a detailed understanding of the energy spacing within the exciton manifold. Dark exciton states are particularly relevant because they represent a channel that reduces radiative efficiency. Here, we apply large in-plane magnetic fields to brighten optically inactive states of CsPbBr3-based nanoplatelets for the first time. This approach allows us to access the dark states and directly determine the dark-bright splitting, which reaches 22 meV for the thinnest nanoplatelets. The splitting is significantly less for thicker nanoplatelets due to reduced exciton confinement. Additionally, the form of the magneto-PL spectrum suggests that dark and bright state populations are nonthermalized, which is indicative of a phonon bottleneck in the exciton relaxation process.
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Affiliation(s)
- Shuli Wang
- Laboratoire
National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228,
Université Grenoble Alpes, Université
Toulouse, Université Toulouse 3, INSA-T, 38042 Grenoble
and 31400 Toulouse, France
| | - Mateusz Dyksik
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Carola Lampe
- Nanospectroscopy
Group and Center for Nanoscience (CeNS), Nano-Institute Munich, Department
of Physics, Ludwig-Maximilians-Universität
München (LMU), Munich 80539 Germany
| | - Moritz Gramlich
- Nanospectroscopy
Group and Center for Nanoscience (CeNS), Nano-Institute Munich, Department
of Physics, Ludwig-Maximilians-Universität
München (LMU), Munich 80539 Germany
| | - Duncan K. Maude
- Laboratoire
National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228,
Université Grenoble Alpes, Université
Toulouse, Université Toulouse 3, INSA-T, 38042 Grenoble
and 31400 Toulouse, France
| | - Michał Baranowski
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Alexander S. Urban
- Nanospectroscopy
Group and Center for Nanoscience (CeNS), Nano-Institute Munich, Department
of Physics, Ludwig-Maximilians-Universität
München (LMU), Munich 80539 Germany
| | - Paulina Plochocka
- Laboratoire
National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228,
Université Grenoble Alpes, Université
Toulouse, Université Toulouse 3, INSA-T, 38042 Grenoble
and 31400 Toulouse, France
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Alessandro Surrente
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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6
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Karpińska M, Jasiński J, Kempt R, Ziegler JD, Sansom H, Taniguchi T, Watanabe K, Snaith HJ, Surrente A, Dyksik M, Maude DK, Kłopotowski Ł, Chernikov A, Kuc A, Baranowski M, Plochocka P. Interlayer excitons in MoSe 2/2D perovskite hybrid heterostructures - the interplay between charge and energy transfer. Nanoscale 2022; 14:8085-8095. [PMID: 35611659 DOI: 10.1039/d2nr00877g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
van der Waals crystals have opened a new and exciting chapter in heterostructure research, removing the lattice matching constraint characteristics of epitaxial semiconductors. They provide unprecedented flexibility for heterostructure design. Combining two-dimensional (2D) perovskites with other 2D materials, in particular transition metal dichalcogenides (TMDs), has recently emerged as an intriguing way to design hybrid opto-electronic devices. However, the excitation transfer mechanism between the layers (charge or energy transfer) remains to be elucidated. Here, we investigate PEA2PbI4/MoSe2 and (BA)2PbI4/MoSe2 heterostructures by combining optical spectroscopy and density functional theory (DFT) calculations. We show that band alignment facilitates charge transfer. Namely, holes are transferred from TMDs to 2D perovskites, while the electron transfer is blocked, resulting in the formation of interlayer excitons. Moreover, we show that the energy transfer mechanism can be turned on by an appropriate alignment of the excitonic states, providing a rule of thumb for the deterministic control of the excitation transfer mechanism in TMD/2D-perovskite heterostructures.
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Affiliation(s)
- M Karpińska
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
- Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland
| | - J Jasiński
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - R Kempt
- Technische Universität Dresden, Bergstr. 66c, 01062 Dresden, Germany
| | - J D Ziegler
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
| | - H Sansom
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - H J Snaith
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - A Surrente
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - M Dyksik
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
| | - Ł Kłopotowski
- Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland
| | - A Chernikov
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062 Dresden, Germany
| | - A Kuc
- Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, 04318 Leipzig, Germany.
| | - M Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - P Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
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7
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Posmyk K, Zawadzka N, Dyksik M, Surrente A, Maude DK, Kazimierczuk T, Babiński A, Molas MR, Paritmongkol W, Mączka M, Tisdale WA, Płochocka P, Baranowski M. Quantification of Exciton Fine Structure Splitting in a Two-Dimensional Perovskite Compound. J Phys Chem Lett 2022; 13:4463-4469. [PMID: 35561248 PMCID: PMC9150119 DOI: 10.1021/acs.jpclett.2c00942] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Applications of two-dimensional (2D) perovskites have significantly outpaced the understanding of many fundamental aspects of their photophysics. The optical response of 2D lead halide perovskites is dominated by strongly bound excitonic states. However, a comprehensive experimental verification of the exciton fine structure splitting and associated transition symmetries remains elusive. Here we employ low temperature magneto-optical spectroscopy to reveal the exciton fine structure of (PEA)2PbI4 (here PEA is phenylethylammonium) single crystals. We observe two orthogonally polarized bright in-plane free exciton (FX) states, both accompanied by a manifold of phonon-dressed states that preserve the polarization of the corresponding FX state. Introducing a magnetic field perpendicular to the 2D plane, we resolve the lowest energy dark exciton state, which although theoretically predicted, has systematically escaped experimental observation (in Faraday configuration) until now. These results corroborate standard multiband, effective-mass theories for the exciton fine structure in 2D perovskites and provide valuable quantification of the fine structure splitting in (PEA)2PbI4.
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Affiliation(s)
- Katarzyna Posmyk
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Natalia Zawadzka
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Mateusz Dyksik
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
- Laboratoire
National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse
3, INSA-T, Toulouse 31400, France
| | - Alessandro Surrente
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Duncan K. Maude
- Laboratoire
National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse
3, INSA-T, Toulouse 31400, France
| | - Tomasz Kazimierczuk
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Adam Babiński
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Maciej R. Molas
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Watcharaphol Paritmongkol
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
- Department
of Chemistry, Massachusetts Institute of
Technology, Cambridge, Massachusetts 02139, United States
| | - Mirosław Mączka
- Institute
of Low Temperature and Structure Research, Polish Academy of Sciences, 50-422 Wrocław, Poland
| | - William A. Tisdale
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Paulina Płochocka
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
- Laboratoire
National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse
3, INSA-T, Toulouse 31400, France
| | - Michał Baranowski
- Department
of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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8
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Abstract
Optically inactive dark exciton states play an important role in light emission processes in semiconductors because they provide an efficient nonradiative recombination channel. Understanding the exciton fine structure in materials with potential applications in light-emitting devices is therefore critical. Here, we investigate the exciton fine structure in the family of two-dimensional (2D) perovskites (PEA)2SnI4, (PEA)2PbI4, and (PEA)2PbBr4. In-plane magnetic field mixes the bright and dark exciton states, brightening the otherwise optically inactive dark exciton. The bright-dark splitting increases with increasing exciton binding energy. Hot photoluminescence is observed, indicative of a non-Boltzmann distribution of the bright-dark exciton populations. We attribute this to the phonon bottleneck, which results from the weak exciton–acoustic phonon coupling in soft 2D perovskites. Hot photoluminescence is responsible for the strong emission observed in these materials, despite the substantial bright-dark exciton splitting.
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Affiliation(s)
- Mateusz Dyksik
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, University Grenoble Alpes, University Toulouse, University Toulouse 3, INSA-T, Grenoble and Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Herman Duim
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Duncan K. Maude
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, University Grenoble Alpes, University Toulouse, University Toulouse 3, INSA-T, Grenoble and Toulouse, France
| | - Michal Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Maria Antonietta Loi
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, University Grenoble Alpes, University Toulouse, University Toulouse 3, INSA-T, Grenoble and Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
- Corresponding author.
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9
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Karpińska M, Liang M, Kempt R, Finzel K, Kamminga M, Dyksik M, Zhang N, Knodlseder C, Maude DK, Baranowski M, Kłopotowski Ł, Ye J, Kuc A, Plochocka P. Nonradiative Energy Transfer and Selective Charge Transfer in a WS 2/(PEA) 2PbI 4 Heterostructure. ACS Appl Mater Interfaces 2021; 13:33677-33684. [PMID: 34227384 DOI: 10.1021/acsami.1c08377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
van der Waals heterostructures are currently the focus of intense investigation; this is essentially due to the unprecedented flexibility offered by the total relaxation of lattice matching requirements and their new and exotic properties compared to the individual layers. Here, we investigate the hybrid transition-metal dichalcogenide/2D perovskite heterostructure WS2/(PEA)2PbI4 (where PEA stands for phenylethylammonium). We present the first density functional theory (DFT) calculations of a heterostructure ensemble, which reveal a novel band alignment, where direct electron transfer is blocked by the organic spacer of the 2D perovskite. In contrast, the valence band forms a cascade from WS2 through the PEA to the PbI4 layer allowing hole transfer. These predictions are supported by optical spectroscopy studies, which provide compelling evidence for both charge transfer and nonradiative transfer of the excitation (energy transfer) between the layers. Our results show that TMD/2D perovskite (where TMD stands for transition-metal dichalcogenides) heterostructures provide a flexible and convenient way to engineer the band alignment.
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Affiliation(s)
- Miriam Karpińska
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, 38042 Grenoble and 31400 Toulouse, France
- Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland
| | - Minpeng Liang
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Roman Kempt
- Technische Universität Dresden, Bergstr. 66c, 01062 Dresden, Germany
| | - Kati Finzel
- Technische Universität Dresden, Bergstr. 66c, 01062 Dresden, Germany
| | - Machteld Kamminga
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Mateusz Dyksik
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, 38042 Grenoble and 31400 Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Nan Zhang
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, 38042 Grenoble and 31400 Toulouse, France
| | - Catherine Knodlseder
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, 38042 Grenoble and 31400 Toulouse, France
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, 38042 Grenoble and 31400 Toulouse, France
| | - Michał Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | | | - Jianting Ye
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Agnieszka Kuc
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, 38042 Grenoble and 31400 Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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10
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Dyksik M, Wang S, Paritmongkol W, Maude DK, Tisdale WA, Baranowski M, Plochocka P. Tuning the Excitonic Properties of the 2D (PEA) 2(MA) n-1Pb nI 3n+1 Perovskite Family via Quantum Confinement. J Phys Chem Lett 2021; 12:1638-1643. [PMID: 33555896 DOI: 10.1021/acs.jpclett.0c03731] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
In atomically thin two-dimensional (2D) crystals, the excitonic properties and band structure scale strongly with the thickness, providing a new playground for the investigation of exciton physics in the ultimate confinement regime. Here, we demonstrate the evolution of the fundamental excitonic properties, such as reduced mass, wave function extension, and exciton binding energy, in the 2D perovskite (PEA)2(MA)n-1PbnI3n+1, for n = 1, 2, 3. These parameters are experimentally determined using optical spectroscopy in a high magnetic field up to 65 T. The observation of the interband Landau level transitions provides direct access to the reduced effective mass μ and band gap Eg. We show that μ increases with the number of inorganic sheets n, reaching the value of three-dimensional (3D) MAPbI3 already for n = 3. Our experimental observations contradict the general expectation that quantum confinement leads to an enhanced carrier mass, showing another aspect of the unprecedented flexibility in the design of the electronic properties of 2D perovskites.
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Affiliation(s)
- Mateusz Dyksik
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Shuli Wang
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France
| | - Watcharaphol Paritmongkol
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France
| | - William A Tisdale
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michal Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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11
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Borodziuk A, Baranowski M, Wojciechowski T, Minikayev R, Sikora B, Maude DK, Plochocka P, Kłopotowski Ł. Excitation efficiency determines the upconversion luminescence intensity of β-NaYF 4:Er 3+,Yb 3+ nanoparticles in magnetic fields up to 70 T. Nanoscale 2020; 12:20300-20307. [PMID: 33001125 DOI: 10.1039/d0nr04252h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lanthanide-doped nanoparticles enable conversion of near-infrared photons to visible ones. This property is envisioned as a basis of a broad range of applications: from optoelectronics, via energy conversion, to bio-sensing and phototherapy. The spectrum of applications can be extended if magnetooptical properties of lanthanide dopants are well understood. However, at present, there are many conflicting reports on the influence of the magnetic field on the upconverted luminescence. In this work, we resolve this discrepancy by performing a comprehensive study of β-NaYF4:Er3+,Yb3+ nanoparticles. Crucially, we show that the magnetic field impacts the luminescence only via a Zeeman-driven detuning between the excitation laser and the absorption transition. On the other hand, the energy transfer and multiphonon relaxation rates are unaffected. We propose a phenomenological model, which qualitatively reproduces the experimental results. The presented results are expected to lead to design of novel, dual-mode opto-magnetic upconverting nanomaterials.
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Affiliation(s)
- Anna Borodziuk
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
| | - Michał Baranowski
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France and Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Tomasz Wojciechowski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
| | - Roman Minikayev
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
| | - Bożena Sikora
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France and Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Łukasz Kłopotowski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
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12
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Urban JM, Chehade G, Dyksik M, Menahem M, Surrente A, Trippé-Allard G, Maude DK, Garrot D, Yaffe O, Deleporte E, Plochocka P, Baranowski M. Revealing Excitonic Phonon Coupling in (PEA) 2(MA) n-1Pb nI 3n+1 2D Layered Perovskites. J Phys Chem Lett 2020; 11:5830-5835. [PMID: 32597181 DOI: 10.1021/acs.jpclett.0c01714] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The family of 2D Ruddlesden-Popper perovskites is currently attracting great interest of the scientific community as highly promising materials for energy harvesting and light emission applications. Despite the fact that these materials are known for decades, only recently has it become apparent that their optical properties are driven by the exciton-phonon coupling, which is controlled by the organic spacers. However, the detailed mechanism of this coupling, which gives rise to complex absorption and emission spectra, is the subject of ongoing controversy. In this work we show that the particularly rich, absorption spectra of (PEA)2(CH3NH3)n-1PbnI3n+1 (where PEA stands for phenylethylammonium and n = 1, 2, 3), are related to a vibronic progression of excitonic transition. In contrast to other two-dimensional perovskites, we observe a coupling to a high-energy (40 meV) phonon mode probably related to the torsional motion of the NH3+ head of the organic spacer.
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Affiliation(s)
- Joanna M Urban
- UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France
- ENS Paris-Saclay, CNRS, CentraleSupelec, LuMIn, Université Paris-Saclay, 91405 Orsay, France
| | - Gabriel Chehade
- ENS Paris-Saclay, CNRS, CentraleSupelec, LuMIn, Université Paris-Saclay, 91405 Orsay, France
| | - Mateusz Dyksik
- UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Matan Menahem
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100, Israel
| | - Alessandro Surrente
- UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France
| | - Gaëlle Trippé-Allard
- ENS Paris-Saclay, CNRS, CentraleSupelec, LuMIn, Université Paris-Saclay, 91405 Orsay, France
| | - Duncan K Maude
- UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France
| | - Damien Garrot
- Groupe d'Etude de la Matière Condensée, Université de Versailles Saint-Quentin-en-Yvelines, Université Paris-Saclay, 45 Avenue des Etats-Unis, 78035 Versailles, France
| | - Omer Yaffe
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100, Israel
| | - Emmanuelle Deleporte
- ENS Paris-Saclay, CNRS, CentraleSupelec, LuMIn, Université Paris-Saclay, 91405 Orsay, France
| | - Paulina Plochocka
- UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Michal Baranowski
- UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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13
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Frisenda R, Sanchez-Santolino G, Papadopoulos N, Urban J, Baranowski M, Surrente A, Maude DK, Garcia-Hernandez M, van der Zant HSJ, Plochocka P, San-Jose P, Castellanos-Gomez A. Symmetry Breakdown in Franckeite: Spontaneous Strain, Rippling, and Interlayer Moiré. Nano Lett 2020; 20:1141-1147. [PMID: 31928013 DOI: 10.1021/acs.nanolett.9b04536] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Franckeite is a naturally occurring layered mineral with a structure composed of alternating stacks of SnS2-like and PbS-like layers. Although this superlattice is composed of a sequence of isotropic two-dimensional layers, it exhibits a spontaneous rippling that makes the material structurally anisotropic. We demonstrate that this rippling comes hand in hand with an inhomogeneous in-plane strain profile and anisotropic electrical, vibrational, and optical properties. We argue that this symmetry breakdown results from a spatial modulation of the van der Waals interaction between layers due to the SnS2-like and PbS-like lattices incommensurability.
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Affiliation(s)
- Riccardo Frisenda
- Materials Science Factory , Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) , Campus de Cantoblanco, Madrid 28049 , Spain
| | - Gabriel Sanchez-Santolino
- Materials Science Factory , Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) , Campus de Cantoblanco, Madrid 28049 , Spain
| | - Nikos Papadopoulos
- Kavli Institute of Nanoscience , Delft University of Technology , Lorentzweg 1 , Delft 2628 CJ , The Netherlands
| | - Joanna Urban
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble, Toulouse 31400 , France
| | - Michal Baranowski
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble, Toulouse 31400 , France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology , Wroclaw University of Science and Technology , Wroclaw 50-370 , Poland
| | - Alessandro Surrente
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble, Toulouse 31400 , France
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble, Toulouse 31400 , France
| | - Mar Garcia-Hernandez
- Materials Science Factory , Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) , Campus de Cantoblanco, Madrid 28049 , Spain
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience , Delft University of Technology , Lorentzweg 1 , Delft 2628 CJ , The Netherlands
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble, Toulouse 31400 , France
| | - Pablo San-Jose
- Materials Science Factory , Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) , Campus de Cantoblanco, Madrid 28049 , Spain
| | - Andres Castellanos-Gomez
- Materials Science Factory , Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) , Campus de Cantoblanco, Madrid 28049 , Spain
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14
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Birowska M, Urban J, Baranowski M, Maude DK, Plochocka P, Szwacki NG. The impact of hexagonal boron nitride encapsulation on the structural and vibrational properties of few layer black phosphorus. Nanotechnology 2019; 30:195201. [PMID: 30699401 DOI: 10.1088/1361-6528/ab0332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The encapsulation of two-dimensional layered materials such as black phosphorus is of paramount importance for their stability in air. However, the encapsulation poses several questions, namely, how it affects, via the weak van der Waals forces, the properties of the black phosphorus and whether these properties can be tuned on demand. Prompted by these questions, we have investigated the impact of hexagonal boron nitride encapsulation on the structural and vibrational properties of few layer black phosphorus, using a first-principles method in the framework of density functional theory. We demonstrate that the encapsulation with hexagonal boron nitride imposes biaxial strain on the black phosphorus material, flattening its puckered structure, by decreasing the thickness of the layers via the increase of the puckered angle and the intra-layer P-P bonds. This work exemplifies the evolution of structural parameters in layered materials after the encapsulation process. We find that after encapsulation, phosphorene (single layer black phosphorous) contracts by 1.1% in the armchair direction and stretches by 1.3% in the zigzag direction, whereas few layer black phosphorus mainly expands by up to 3% in the armchair direction. However, these relatively small strains induced by the hexagonal BN, lead to significant changes in the vibrational properties of black phosphorus, with the redshifts of up to 10 cm-1 of the high frequency optical mode A g 1. In general, structural changes induced by the encapsulation process open the door to substrate controlled strain engineering in two-dimensional crystals.
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Affiliation(s)
- Magdalena Birowska
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
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15
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Lin J, Han T, Piot BA, Wu Z, Xu S, Long G, An L, Cheung P, Zheng PP, Plochocka P, Dai X, Maude DK, Zhang F, Wang N. Determining Interaction Enhanced Valley Susceptibility in Spin-Valley-Locked MoS 2. Nano Lett 2019; 19:1736-1742. [PMID: 30720286 DOI: 10.1021/acs.nanolett.8b04731] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Two-dimensional transition metal dichalcogenides (TMDCs) are recently emerged electronic systems with various novel properties, such as spin-valley locking, circular dichroism, valley Hall effect, and superconductivity. The reduced dimensionality and large effective masses further produce unconventional many-body interaction effects. Here we reveal strong interaction effects in the conduction band of MoS2 by transport experiment. We study the massive Dirac electron Landau levels (LL) in high-quality MoS2 samples with field-effect mobilities of 24 000 cm2/(V·s) at 1.2 K. We identify the valley-resolved LLs and low-lying polarized LLs using the Lifshitz-Kosevitch formula. By further tracing the LL crossings in the Landau fan diagram, we unambiguously determine the density-dependent valley susceptibility and the interaction enhanced g-factor from 12.7 to 23.6. Near integer ratios of Zeeman-to-cyclotron energies, we discover LL anticrossings due to the formation of quantum Hall Ising ferromagnets, the valley polarizations of which appear to be reversible by tuning the density or an in-plane magnetic field. Our results provide evidence for many-body interaction effects in the conduction band of MoS2 and establish a fertile ground for exploring strongly correlated phenomena of massive Dirac electrons.
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Affiliation(s)
- Jiangxiazi Lin
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Tianyi Han
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Benjamin A Piot
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS-UGA-UPS-INSA-EMFL , F-38042 Grenoble , France
| | - Zefei Wu
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Shuigang Xu
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Gen Long
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Liheng An
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Patrick Cheung
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | - Peng-Peng Zheng
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS-UGA-UPS-INSA-EMFL , F-31400 Toulouse , France
| | - Xi Dai
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS-UGA-UPS-INSA-EMFL , F-31400 Toulouse , France
| | - Fan Zhang
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | - Ning Wang
- Department of Physics and Center for Quantum Materials , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong , China
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16
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Zhang N, Surrente A, Baranowski M, Maude DK, Gant P, Castellanos-Gomez A, Plochocka P. Moiré Intralayer Excitons in a MoSe 2/MoS 2 Heterostructure. Nano Lett 2018; 18:7651-7657. [PMID: 30403876 DOI: 10.1021/acs.nanolett.8b03266] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Spatially periodic structures with a long-range period, referred to as a moiré pattern, can be obtained in van der Waals bilayers in the presence of a small stacking angle or of lattice mismatch between the monolayers. Theoretical predictions suggest that the resulting spatially periodic variation of the band structure modifies the optical properties of both intra- and interlayer excitons of transition metal dichalcogenide heterostructures. Here, we report on the impact of the moiré pattern formed in a MoSe2/MoS2 heterobilayer encapsulated in hexagonal boron nitride. The periodic in-plane potential results in a splitting of the MoSe2 exciton and trion in emission and (for the exciton) absorption spectra. The observed energy difference between the split peaks is fully consistent with theoretical predictions.
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Affiliation(s)
- Nan Zhang
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
| | - Alessandro Surrente
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
| | - Michał Baranowski
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology , Wroclaw University of Science and Technology , 50-370 Wroclaw , Poland
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
| | - Patricia Gant
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM) , Consejo Superior de Investigaciones Cientficas (CSIC) , Sor Juana Ins de la Cruz 3 , 28049 Madrid , Spain
| | - Andres Castellanos-Gomez
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM) , Consejo Superior de Investigaciones Cientficas (CSIC) , Sor Juana Ins de la Cruz 3 , 28049 Madrid , Spain
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
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17
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Kłopotowski Ł, Czechowski N, Mitioglu AA, Backes C, Maude DK, Plochocka P. Long-lived photoluminescence polarization of localized excitons in liquid exfoliated monolayer enriched WS 2. Nanotechnology 2018; 29:335703. [PMID: 29790860 DOI: 10.1088/1361-6528/aac73e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Monolayer transition metal dichalcogenides (TMDs) constitute a family of materials, in which coupled spin-valley physics can be explored and which could find applications in novel optoelectronic devices. However, before applications can be designed, a scalable method of monolayer extraction is required. Liquid phase exfoliation is a technique providing large quantities of the monolayer material, but the spin-valley properties of thus obtained TMDs are unknown. In this work, we employ steady-state and time-resolved photoluminescence (PL) to investigate the relaxation dynamics of localized excitons (LXs) in liquid exfoliated WS2. The results reveal that the circular polarization lifetime of the PL exceeds by at least an order of magnitude the PL lifetime. A rate equations model allows us to reproduce quantitatively the experimental data and to conclude that the observed large and long-lived PL polarization originates from efficient trapping of free excitons at localization sites hindering the intervalley relaxation. Furthermore, our results show that the depolarization process is inefficient for LXs. We discuss various mechanisms leading to this effect such as suppression of intervalley scattering of the LXs or inefficient spin relaxation of the holes.
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Affiliation(s)
- Ł Kłopotowski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
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18
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Surrente A, Kłopotowski Ł, Zhang N, Baranowski M, Mitioglu AA, Ballottin MV, Christianen PCM, Dumcenco D, Kung YC, Maude DK, Kis A, Plochocka P. Intervalley Scattering of Interlayer Excitons in a MoS 2/MoSe 2/MoS 2 Heterostructure in High Magnetic Field. Nano Lett 2018; 18:3994-4000. [PMID: 29791166 DOI: 10.1021/acs.nanolett.8b01484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Degenerate extrema in the energy dispersion of charge carriers in solids, also referred to as valleys, can be regarded as a binary quantum degree of freedom, which can potentially be used to implement valleytronic concepts in van der Waals heterostructures based on transition metal dichalcogenides. Using magneto-photoluminescence spectroscopy, we achieve a deeper insight into the valley polarization and depolarization mechanisms of interlayer excitons formed across a MoS2/MoSe2/MoS2 heterostructure. We account for the nontrivial behavior of the valley polarization as a function of the magnetic field by considering the interplay between exchange interaction and phonon-mediated intervalley scattering in a system consisting of Zeeman-split energy levels. Our results represent a crucial step toward the understanding of the properties of interlayer excitons with strong implications for the implementation of atomically thin valleytronic devices.
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Affiliation(s)
- Alessandro Surrente
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
| | - Łukasz Kłopotowski
- Institute of Physics , Polish Academy of Sciences , Al. Lotników 32/46 , 02-668 Warsaw , Poland
| | - Nan Zhang
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
| | - Michal Baranowski
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology , Wroclaw University of Science and Technology , 50-370 Wroclaw , Poland
| | - Anatolie A Mitioglu
- High Field Magnet Laboratory (HFML - EMFL) , Radboud University , 6525 ED Nijmegen , The Netherlands
| | - Mariana V Ballottin
- High Field Magnet Laboratory (HFML - EMFL) , Radboud University , 6525 ED Nijmegen , The Netherlands
| | - Peter C M Christianen
- High Field Magnet Laboratory (HFML - EMFL) , Radboud University , 6525 ED Nijmegen , The Netherlands
| | - Dumitru Dumcenco
- Electrical Engineering Institute and Institute of Materials Science and Engineering , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
- Department of Quantum Matter Physics , Université de Genève , 24 quai Ernest Ansermet , CH-1211 Geneva , Switzerland
| | - Yen-Cheng Kung
- Electrical Engineering Institute and Institute of Materials Science and Engineering , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
| | - Andras Kis
- Electrical Engineering Institute and Institute of Materials Science and Engineering , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses , UPR 3228, CNRS-UGA-UPS-INSA, 38042/31400 Grenoble/Toulouse , France
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19
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Urban JM, Baranowski M, Surrente A, Wlodarczyk D, Suchocki A, Long G, Wang Y, Klopotowski L, Wang N, Maude DK, Plochocka P. Observation of A Raman mode splitting in few layer black phosphorus encapsulated with hexagonal boron nitride. Nanoscale 2017; 9:19298-19303. [PMID: 29192915 DOI: 10.1039/c7nr05588a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigate the impact of encapsulation with hexagonal boron nitride (h-BN) on the Raman spectrum of few layer black phosphorus. The encapsulation results in a significant reduction of the line width of the Raman modes of black phosphorus, due to a reduced phonon scattering rate. We observe a so far elusive peak in the Raman spectra ∼4 cm-1 above the A mode in trilayer and thicker flakes, which had not been observed experimentally. The newly observed mode originates from the strong black phosphorus inter-layer interaction, which induces a hardening of the surface atom vibration with respect to the corresponding modes of the inner layers. The observation of this mode suggests a significant impact of h-BN encapsulation on the properties of black phosphorus and can serve as an indicator of the quality of its surface.
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Affiliation(s)
- J M Urban
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
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20
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Baranowski M, Surrente A, Klopotowski L, Urban JM, Zhang N, Maude DK, Wiwatowski K, Mackowski S, Kung YC, Dumcenco D, Kis A, Plochocka P. Probing the Interlayer Exciton Physics in a MoS 2/MoSe 2/MoS 2 van der Waals Heterostructure. Nano Lett 2017; 17:6360-6365. [PMID: 28895745 DOI: 10.1021/acs.nanolett.7b03184] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Stacking atomic monolayers of semiconducting transition metal dichalcogenides (TMDs) has emerged as an effective way to engineer their properties. In principle, the staggered band alignment of TMD heterostructures should result in the formation of interlayer excitons with long lifetimes and robust valley polarization. However, these features have been observed simultaneously only in MoSe2/WSe2 heterostructures. Here we report on the observation of long-lived interlayer exciton emission in a MoS2/MoSe2/MoS2 trilayer van der Waals heterostructure. The interlayer nature of the observed transition is confirmed by photoluminescence spectroscopy, as well as by analyzing the temporal, excitation power, and temperature dependence of the interlayer emission peak. The observed complex photoluminescence dynamics suggests the presence of quasi-degenerate momentum-direct and momentum-indirect bandgaps. We show that circularly polarized optical pumping results in long-lived valley polarization of interlayer exciton. Intriguingly, the interlayer exciton photoluminescence has helicity opposite to the excitation. Our results show that through a careful choice of the TMDs forming the van der Waals heterostructure it is possible to control the circular polarization of the interlayer exciton emission.
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Affiliation(s)
- M Baranowski
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA , 143 avenue de Rangueil, 31400 Toulouse, France
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology , Wybrzeze Wyspianskiego 27, 50-370 Wrocaw, Poland
| | - A Surrente
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA , 143 avenue de Rangueil, 31400 Toulouse, France
| | - L Klopotowski
- Institute of Physics, Polish Academy of Sciences , al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - J M Urban
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA , 143 avenue de Rangueil, 31400 Toulouse, France
| | - N Zhang
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA , 143 avenue de Rangueil, 31400 Toulouse, France
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA , 143 avenue de Rangueil, 31400 Toulouse, France
| | - K Wiwatowski
- Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University , Grudziadzka 5, 87-100 Torun, Poland
| | - S Mackowski
- Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University , Grudziadzka 5, 87-100 Torun, Poland
| | - Y C Kung
- Electrical Engineering Institute and Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - D Dumcenco
- Electrical Engineering Institute and Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - A Kis
- Electrical Engineering Institute and Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - P Plochocka
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA , 143 avenue de Rangueil, 31400 Toulouse, France
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21
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Surrente A, Dumcenco D, Yang Z, Kuc A, Jing Y, Heine T, Kung YC, Maude DK, Kis A, Plochocka P. Defect Healing and Charge Transfer-Mediated Valley Polarization in MoS 2/MoSe 2/MoS 2 Trilayer van der Waals Heterostructures. Nano Lett 2017; 17:4130-4136. [PMID: 28603999 DOI: 10.1021/acs.nanolett.7b00904] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Monolayer transition metal dichalcogenides (TMDCs) grown by chemical vapor deposition (CVD) are plagued by a significantly lower optical quality compared to exfoliated TMDCs. In this work, we show that the optical quality of CVD-grown MoSe2 is completely recovered if the material is sandwiched in MoS2/MoSe2/MoS2 trilayer van der Waals heterostructures. We show by means of density functional theory that this remarkable and unexpected result is due to defect healing: S atoms of the more reactive MoS2 layers are donated to heal Se vacancy defects in the middle MoSe2 layer. In addition, the trilayer structure exhibits a considerable charge-transfer mediated valley polarization of MoSe2 without the need for resonant excitation. Our fabrication approach, relying solely on simple flake transfer technique, paves the way for the scalable production of large-area TMDC materials with excellent optical quality.
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Affiliation(s)
- Alessandro Surrente
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble and Toulouse, France
| | - Dumitru Dumcenco
- Electrical Engineering Institute and Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Zhuo Yang
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble and Toulouse, France
| | - Agnieszka Kuc
- Wilhelm Ostwald Institute of Physical and Theoretical Chemistry Leipzig, University of Leipzig , 04109 Saxony Germany
- School of Engineering and Science, Jacobs University Bremen , Campus Ring 1, 28759 Bremen, Germany
| | - Yu Jing
- Wilhelm Ostwald Institute of Physical and Theoretical Chemistry Leipzig, University of Leipzig , 04109 Saxony Germany
| | - Thomas Heine
- Wilhelm Ostwald Institute of Physical and Theoretical Chemistry Leipzig, University of Leipzig , 04109 Saxony Germany
- School of Engineering and Science, Jacobs University Bremen , Campus Ring 1, 28759 Bremen, Germany
| | - Yen-Cheng Kung
- Electrical Engineering Institute and Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble and Toulouse, France
| | - Andras Kis
- Electrical Engineering Institute and Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA , Grenoble and Toulouse, France
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22
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Yang Z, Surrente A, Tutuncuoglu G, Galkowski K, Cazaban-Carrazé M, Amaduzzi F, Leroux P, Maude DK, Fontcuberta I Morral A, Plochocka P. Revealing Large-Scale Homogeneity and Trace Impurity Sensitivity of GaAs Nanoscale Membranes. Nano Lett 2017; 17:2979-2984. [PMID: 28440658 DOI: 10.1021/acs.nanolett.7b00257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
III-V nanostructures have the potential to revolutionize optoelectronics and energy harvesting. For this to become a reality, critical issues such as reproducibility and sensitivity to defects should be resolved. By discussing the optical properties of molecular beam epitaxy (MBE) grown GaAs nanomembranes we highlight several features that bring them closer to large scale applications. Uncapped membranes exhibit a very high optical quality, expressed by extremely narrow neutral exciton emission, allowing the resolution of the more complex excitonic structure for the first time. Capping of the membranes with an AlGaAs shell results in a strong increase of emission intensity but also in a shift and broadening of the exciton peak. This is attributed to the existence of impurities in the shell, beyond MBE-grade quality, showing the high sensitivity of these structures to the presence of impurities. Finally, emission properties are identical at the submicron and submillimeter scale, demonstrating the potential of these structures for large scale applications.
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Affiliation(s)
- Z Yang
- Laboratoire National des Champs Magnétiques Intenses , CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
| | - A Surrente
- Laboratoire National des Champs Magnétiques Intenses , CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
| | - G Tutuncuoglu
- Laboratory of Semiconductor Material, École Polytechnique Fédérale de Lausanne , 1015 Lausanne, Switzerland
| | - K Galkowski
- Laboratoire National des Champs Magnétiques Intenses , CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw , Pasteura 5, 02-093 Warsaw, Poland
| | - M Cazaban-Carrazé
- Laboratoire National des Champs Magnétiques Intenses , CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
| | - F Amaduzzi
- Laboratory of Semiconductor Material, École Polytechnique Fédérale de Lausanne , 1015 Lausanne, Switzerland
| | - P Leroux
- Laboratory of Semiconductor Material, École Polytechnique Fédérale de Lausanne , 1015 Lausanne, Switzerland
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses , CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
| | - A Fontcuberta I Morral
- Laboratory of Semiconductor Material, École Polytechnique Fédérale de Lausanne , 1015 Lausanne, Switzerland
| | - P Plochocka
- Laboratoire National des Champs Magnétiques Intenses , CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
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23
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Yang Z, Surrente A, Galkowski K, Bruyant N, Maude DK, Haghighirad AA, Snaith HJ, Plochocka P, Nicholas RJ. Unraveling the Exciton Binding Energy and the Dielectric Constant in Single-Crystal Methylammonium Lead Triiodide Perovskite. J Phys Chem Lett 2017; 8:1851-1855. [PMID: 28393517 DOI: 10.1021/acs.jpclett.7b00524] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We have accurately determined the exciton binding energy and reduced mass of single crystals of methylammonium lead triiodide using magneto-reflectivity at very high magnetic fields. The single crystal has excellent optical properties with a narrow line width of ∼3 meV for the excitonic transitions and a 2s transition that is clearly visible even at zero magnetic field. The exciton binding energy of 16 ± 2 meV in the low-temperature orthorhombic phase is almost identical to the value found in polycrystalline samples, crucially ruling out any possibility that the exciton binding energy depends on the grain size. In the room-temperature tetragonal phase, an upper limit for the exciton binding energy of 12 ± 4 meV is estimated from the evolution of 1s-2s splitting at high magnetic field.
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Affiliation(s)
- Zhuo Yang
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
| | - Alessandro Surrente
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
| | - Krzysztof Galkowski
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw , Pasteura 5, 02-093 Warsaw, Poland
| | - Nicolas Bruyant
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
| | | | - Henry J Snaith
- University of Oxford , Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse 31400, France
| | - Robin J Nicholas
- University of Oxford , Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
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24
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Galkowski K, Mitioglu AA, Surrente A, Yang Z, Maude DK, Kossacki P, Eperon GE, Wang JTW, Snaith HJ, Plochocka P, Nicholas RJ. Spatially resolved studies of the phases and morphology of methylammonium and formamidinium lead tri-halide perovskites. Nanoscale 2017; 9:3222-3230. [PMID: 28225143 DOI: 10.1039/c7nr00355b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The family of organic-inorganic tri-halide perovskites including MA (MethylAmmonium)PbI3, MAPbI3-xClx, FA (FormAmidinium)PbI3 and FAPbBr3 are having a tremendous impact on the field of photovoltaic cells due to the combination of their ease of deposition and high energy conversion efficiencies. Device performance, however, is known to be still significantly affected by the presence of inhomogeneities. Here we report on a study of temperature dependent micro-photoluminescence which shows a strong spatial inhomogeneity related to the presence of microcrystalline grains, which can be both bright and dark. In all of the tri-iodide based materials there is evidence that the tetragonal to orthorhombic phase transition observed around 160 K does not occur uniformly across the sample with domain formation related to the underlying microcrystallite grains, some of which remain in the high temperature, tetragonal, phase even at very low temperatures. At low temperature the tetragonal domains can be significantly influenced by local defects in the layers or the introduction of residual levels of chlorine in mixed halide layers or dopant atoms such as aluminium. We see that improvements in room temperature energy conversion efficiency appear to be directly related to reductions in the proportions of the layer which remain in the tetragonal phase at low temperature. In FAPbBr3 a more macroscopic domain structure is observed with large numbers of grains forming phase correlated regions.
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Affiliation(s)
- K Galkowski
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France. and Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - A A Mitioglu
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France. and Institute of Applied Physics, Academiei Str. 5, Chisinau, MD-2028, Republic of Moldova
| | - A Surrente
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France.
| | - Z Yang
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France.
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France.
| | - P Kossacki
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - G E Eperon
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK.
| | - J T-W Wang
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK.
| | - H J Snaith
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK.
| | - P Plochocka
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France.
| | - R J Nicholas
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK.
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25
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Osherov A, Hutter EM, Galkowski K, Brenes R, Maude DK, Nicholas RJ, Plochocka P, Bulović V, Savenije TJ, Stranks SD. The Impact of Phase Retention on the Structural and Optoelectronic Properties of Metal Halide Perovskites. Adv Mater 2016; 28:10757-10763. [PMID: 27757994 DOI: 10.1002/adma.201604019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/10/2016] [Indexed: 06/06/2023]
Abstract
The extent to which the soft structural properties of metal halide perovskites affect their optoelectronic properties is unclear. X-ray diffraction and micro-photoluminescence measurements are used to show that there is a coexistence of both tetragonal and orthorhombic phases through the low-temperature phase transition, and that cycling through this transition can lead to structural changes and enhanced optoelectronic properties.
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Affiliation(s)
- Anna Osherov
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Eline M Hutter
- Opto-electronic Materials Section, Department of Chemical Engineering, Delft University of Technology, van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Krzysztof Galkowski
- Laboratoire National des Champs Magnetiques Intenses, CNRS-UJF-UPS-INSA, 143 avenue de Rangueil, 31400, Toulouse, France
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw - Pasteura 5, 02-093, Warsaw, Poland
| | - Roberto Brenes
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Duncan K Maude
- Laboratoire National des Champs Magnetiques Intenses, CNRS-UJF-UPS-INSA, 143 avenue de Rangueil, 31400, Toulouse, France
| | - Robin J Nicholas
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Paulina Plochocka
- Laboratoire National des Champs Magnetiques Intenses, CNRS-UJF-UPS-INSA, 143 avenue de Rangueil, 31400, Toulouse, France
| | - Vladimir Bulović
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Tom J Savenije
- Opto-electronic Materials Section, Department of Chemical Engineering, Delft University of Technology, van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Samuel D Stranks
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
- Cavendish Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
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26
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Kłopotowski Ł, Backes C, Mitioglu AA, Vega-Mayoral V, Hanlon D, Coleman JN, Ivanov VY, Maude DK, Plochocka P. Revealing the nature of excitons in liquid exfoliated monolayer tungsten disulphide. Nanotechnology 2016; 27:425701. [PMID: 27606691 DOI: 10.1088/0957-4484/27/42/425701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Transition metal dichalcogenides (TMD) hold promise for applications in novel optoelectronic devices. There is therefore a need for materials that can be obtained in large quantities and with well understood optical properties. In this report, we present thorough photoluminescence (PL) investigations of monolayer tungsten disulphide obtained via liquid phase exfoliation. As shown by microscopy studies, the exfoliated nanosheets have dimensions of tens of nanometers and thickness of 2.5 monolayers on average. The monolayer content is about 20%. Our studies show that at low temperature the PL is dominated by excitons localized on nanosheet edges. As a consequence, the PL is strongly sensitive to the environment and exhibits an enhanced splitting in magnetic field. As the temperature is increased, the excitons are thermally excited out of the defect states and the dominant transition is that of the negatively charged exciton. Furthermore, upon excitation with a circularly polarized light, the PL retains a degree of polarization reaching 50% and inherited from the valley polarized photoexcited excitons. The studies of PL dynamics reveal that the PL lifetime is on the order of 10 ps, which is probably limited by non-radiative processes. Our results underline the potential of liquid exfoliated TMD monolayers in large scale optoelectronic devices.
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Affiliation(s)
- Ł Kłopotowski
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikw 32/46, 02-668 Warsaw, Poland
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Alexander-Webber JA, Huang J, Maude DK, Janssen TJBM, Tzalenchuk A, Antonov V, Yager T, Lara-Avila S, Kubatkin S, Yakimova R, Nicholas RJ. Giant quantum Hall plateaus generated by charge transfer in epitaxial graphene. Sci Rep 2016; 6:30296. [PMID: 27456765 PMCID: PMC4960615 DOI: 10.1038/srep30296] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/24/2016] [Indexed: 11/09/2022] Open
Abstract
Epitaxial graphene has proven itself to be the best candidate for quantum electrical resistance standards due to its wide quantum Hall plateaus with exceptionally high breakdown currents. However one key underlying mechanism, a magnetic field dependent charge transfer process, is yet to be fully understood. Here we report measurements of the quantum Hall effect in epitaxial graphene showing the widest quantum Hall plateau observed to date extending over 50 T, attributed to an almost linear increase in carrier density with magnetic field. This behaviour is strong evidence for field dependent charge transfer from charge reservoirs with exceptionally high densities of states in close proximity to the graphene. Using a realistic framework of broadened Landau levels we model the densities of donor states and predict the field dependence of charge transfer in excellent agreement with experimental results, thus providing a guide towards engineering epitaxial graphene for applications such as quantum metrology.
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Affiliation(s)
- J A Alexander-Webber
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - J Huang
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France
| | - T J B M Janssen
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - A Tzalenchuk
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom.,Department of Physics, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom
| | - V Antonov
- Department of Physics, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom
| | - T Yager
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - S Lara-Avila
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - S Kubatkin
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - R Yakimova
- Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83 Linköping, Sweden
| | - R J Nicholas
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
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Piot BA, Desrat W, Maude DK, Kazazis D, Cavanna A, Gennser U. Disorder-Induced Stabilization of the Quantum Hall Ferromagnet. Phys Rev Lett 2016; 116:106801. [PMID: 27015501 DOI: 10.1103/physrevlett.116.106801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Indexed: 06/05/2023]
Abstract
We report on an absolute measurement of the electronic spin polarization of the ν=1 integer quantum Hall state. The spin polarization is extracted in the vicinity of ν=1 (including at exactly ν=1) via resistive NMR experiments performed at different magnetic fields (electron densities) and Zeeman energy configurations. At the lowest magnetic fields, the polarization is found to be complete in a narrow region around ν=1. Increasing the magnetic field (electron density) induces a significant depolarization of the system, which we attribute to a transition between the quantum Hall ferromagnet and the Skyrmion glass phase theoretically expected as the ratio between Coulomb interactions and disorder is increased. These observations account for the fragility of the polarization previously observed in high mobility 2D electron gas and experimentally demonstrate the existence of an optimal amount of disorder to stabilize the ferromagnetic state.
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Affiliation(s)
- B A Piot
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS-UGA-UPS-INSA-EMFL, F-38042 Grenoble, France
| | - W Desrat
- Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, F-34095 Montpellier, France
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS-UGA-UPS-INSA-EMFL, F-31400 Toulouse, France
| | - D Kazazis
- CNRS, Laboratoire de Photonique et de Nanostructures (LPN), 91460 Marcoussis, France
| | - A Cavanna
- CNRS, Laboratoire de Photonique et de Nanostructures (LPN), 91460 Marcoussis, France
| | - U Gennser
- CNRS, Laboratoire de Photonique et de Nanostructures (LPN), 91460 Marcoussis, France
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Desrat W, Piot BA, Maude DK, Wasilewski ZR, Henini M, Airey R. W line shape in the resistively detected nuclear magnetic resonance. J Phys Condens Matter 2015; 27:275801. [PMID: 26086605 DOI: 10.1088/0953-8984/27/27/275801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The resistively detected nuclear magnetic resonance (RDNMR) performed on a two-dimensional electron gas is known to exhibit a peculiar 'dispersive' line shape at some filling factors, especially around ν = 1. Here, we study in detail the inversion of the dispersive line shape as a function of the filling factor from ν = 1 to 2/3. The RDNMR spectra show a new characteristic W line shape in the longitudinal resistance, whereas dispersive lines detected in the Hall resistance remain unchanged. This W resonance, like the dispersive line, can be fitted correctly by a model of two independent response functions, which are the signatures of polarized and unpolarized electronic sub-systems.
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Affiliation(s)
- W Desrat
- Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, Montpellier, France. Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble, France
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Mitioglu AA, Plochocka P, Granados del Aguila Á, Christianen PCM, Deligeorgis G, Anghel S, Kulyuk L, Maude DK. Optical Investigation of Monolayer and Bulk Tungsten Diselenide (WSe₂) in High Magnetic Fields. Nano Lett 2015; 15:4387-4392. [PMID: 26065723 DOI: 10.1021/acs.nanolett.5b00626] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optical spectroscopy in high magnetic fields B ≤ 65 T is used to reveal the very different nature of carriers in monolayer and bulk transition metal dichalcogenides. In monolayer WSe2, the exciton emission shifts linearly with the magnetic field and exhibits a splitting that originates from the magnetic field induced valley splitting. The monolayer data can be described using a single particle picture with a Dirac-like Hamiltonian for massive Dirac Fermions, with an additional term to phenomenologically include the valley splitting. In contrast, in bulk WSe2 where the inversion symmetry is restored, transmission measurements show a distinctly excitonic behavior with absorption to the 1s and 2s states. Magnetic field induces a spin splitting together with a small diamagnetic shift and cyclotron like behavior at high fields, which is best described within the hydrogen model.
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Affiliation(s)
- A A Mitioglu
- †Laboratoire National des Champs Magnétiques Intenses, CNRS-EMFL-UJF-UPS-INSA, Grenoble and Toulouse, France
- ∥Institute of Applied Physics, Academiei Str. 5, Chisinau, MD-2028, Republic of Moldova
| | - P Plochocka
- †Laboratoire National des Champs Magnétiques Intenses, CNRS-EMFL-UJF-UPS-INSA, Grenoble and Toulouse, France
| | - Á Granados del Aguila
- ‡High Field Magnet Laboratory (HFML-EMFL), Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - P C M Christianen
- ‡High Field Magnet Laboratory (HFML-EMFL), Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - G Deligeorgis
- §Microelectronics Research Group, FORTH-IESL, 71110 Heraklion, Crete Greece
| | - S Anghel
- ∥Institute of Applied Physics, Academiei Str. 5, Chisinau, MD-2028, Republic of Moldova
| | - L Kulyuk
- ∥Institute of Applied Physics, Academiei Str. 5, Chisinau, MD-2028, Republic of Moldova
| | - D K Maude
- †Laboratoire National des Champs Magnétiques Intenses, CNRS-EMFL-UJF-UPS-INSA, Grenoble and Toulouse, France
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Vorobyova JS, Vorob'ev AB, Prinz VY, Toropov AI, Maude DK. Magnetotransport in two-dimensional electron gas in helical nanomembranes. Nano Lett 2015; 15:1673-1678. [PMID: 25650698 DOI: 10.1021/nl504305s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Heterostructures containing high-mobility two-dimensional electron gas were rolled into freestanding helically shaped contacted Hall bars. Magnetotransport measurements in these structures at high magnetic fields revealed minima in the longitudinal magnetoresistance corresponding to integer and fractional filling factors. A strong asymmetry of the longitudinal magnetoresistance with respect to the external magnetic field direction was observed. For this new type of structures, an edge state picture was considered, and calculations based on the Landauer-Büttiker formalism are performed.
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Affiliation(s)
- Julia S Vorobyova
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Science , pr. Lavrentieva 13, 630090 Novosibirsk, Russia
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Jadczak J, Plochocka P, Mitioglu A, Breslavetz I, Royo M, Bertoni A, Goldoni G, Smolenski T, Kossacki P, Kretinin A, Shtrikman H, Maude DK. Unintentional high-density p-type modulation doping of a GaAs/AlAs core-multishell nanowire. Nano Lett 2014; 14:2807-2814. [PMID: 24745828 DOI: 10.1021/nl500818k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Achieving significant doping in GaAs/AlAs core/shell nanowires (NWs) is of considerable technological importance but remains a challenge due to the amphoteric behavior of the dopant atoms. Here we show that placing a narrow GaAs quantum well in the AlAs shell effectively getters residual carbon acceptors leading to an unintentional p-type doping. Magneto-optical studies of such a GaAs/AlAs core-multishell NW reveal quantum confined emission. Theoretical calculations of NW electronic structure confirm quantum confinement of carriers at the core/shell interface due to the presence of ionized carbon acceptors in the 1 nm GaAs layer in the shell. Microphotoluminescence in high magnetic field shows a clear signature of avoided crossings of the n = 0 Landau level emission line with the n = 2 Landau level TO phonon replica. The coupling is caused by the resonant hole-phonon interaction, which points to a large two-dimensional hole density in the structure.
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Affiliation(s)
- J Jadczak
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA , 143, avenue de Rangueil, 31400 Toulouse, France
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33
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Alexander-Webber JA, Baker AMR, Janssen TJBM, Tzalenchuk A, Lara-Avila S, Kubatkin S, Yakimova R, Piot BA, Maude DK, Nicholas RJ. Phase space for the breakdown of the quantum Hall effect in epitaxial graphene. Phys Rev Lett 2013; 111:096601. [PMID: 24033057 DOI: 10.1103/physrevlett.111.096601] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Indexed: 06/02/2023]
Abstract
We report the phase space defined by the quantum Hall effect breakdown in polymer gated epitaxial graphene on SiC (SiC/G) as a function of temperature, current, carrier density, and magnetic fields up to 30 T. At 2 K, breakdown currents (I(c)) almost 2 orders of magnitude greater than in GaAs devices are observed. The phase boundary of the dissipationless state (ρ(xx)=0) shows a [1-(T/T(c))2] dependence and persists up to T(c)>45 K at 29 T. With magnetic field I(c) was found to increase ∝B(3/2) and T(c)∝B2. As the Fermi energy pproaches the Dirac point, the ν=2 quantized Hall plateau appears continuously from fields as low as 1 T up to at least 19 T due to a strong magnetic field dependence of the carrier density.
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Affiliation(s)
- J A Alexander-Webber
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
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34
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Plochocka P, Mitioglu AA, Maude DK, Rikken GLJA, del Águila AG, Christianen PCM, Kacman P, Shtrikman H. High magnetic field reveals the nature of excitons in a single GaAs/AlAs core/shell nanowire. Nano Lett 2013; 13:2442-2447. [PMID: 23634970 DOI: 10.1021/nl400417x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Magneto-photoluminescence measurements of individual zinc-blende GaAs/AlAs core/shell nanowires are reported. At low temperature, a strong emission line at 1.507 eV is observed under low power (nW) excitation. Measurements performed in high magnetic field allowed us to detect in this emission several lines associated with excitons bound to defect pairs. Such lines were observed before in epitaxial GaAs of very high quality, as reported by Kunzel and Ploog. This demonstrates that the optical quality of our GaAs/AlAs core/shell nanowires is comparable to the best GaAs layers grown by molecular beam epitaxy. Moreover, strong free exciton emission is observed even at room temperature. The bright optical emission of our nanowires in room temperature should open the way for numerous optoelectronic device applications.
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Affiliation(s)
- P Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UJF-UPS-INSA, Grenoble and Toulouse, France.
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35
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Amado M, Diez E, Rossella F, Bellani V, López-Romero D, Maude DK. Magneto-transport of graphene and quantum phase transitions in the quantum Hall regime. J Phys Condens Matter 2012; 24:305302. [PMID: 22771627 DOI: 10.1088/0953-8984/24/30/305302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this paper we show the electronic transport and the quantum phase transitions that characterize the quantum Hall regime in graphene placed on SiO(2) substrates at magnetic fields up to 28 T and temperatures down to 4 K. The analysis of the temperature dependence of the Hall and longitudinal resistivity reveals intriguing non-universalities of the critical exponents of the plateau-insulator transition. These exponents depend on the type of disorder that governs the electrical transport and its characterization is important for the design and fabrication of novel graphene nano-devices.
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Affiliation(s)
- Mario Amado
- Laboratorio de Bajas Temperaturas, Universidad de Salamanca, 37008 Salamanca, Spain.
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36
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Schneider JM, Piot BA, Sheikin I, Maude DK. Using the de Haas-van Alphen effect to map out the closed three-dimensional Fermi surface of natural graphite. Phys Rev Lett 2012; 108:117401. [PMID: 22540506 DOI: 10.1103/physrevlett.108.117401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Indexed: 05/31/2023]
Abstract
The Fermi surface of graphite has been mapped out using de Haas-van Alphen (dHvA) measurements at low temperature with in-situ rotation. For tilt angles θ>60° between the magnetic field and the c axis, the majority electron and hole dHvA periods no longer follow a cos(θ) behavior demonstrating that graphite has a three-dimensional closed Fermi surface. The Fermi surface of graphite is accurately described by highly elongated ellipsoids. A comparison with the calculated Fermi surface suggests that the Slonczewski-Weiss-McClure trigonal warping parameter γ(3) is significantly larger than previously thought.
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Affiliation(s)
- J M Schneider
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble, France
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37
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Stern M, Piot BA, Vardi Y, Umansky V, Plochocka P, Maude DK, Bar-Joseph I. NMR probing of the spin polarization of the ν=5/2 quantum Hall state. Phys Rev Lett 2012; 108:066810. [PMID: 22401109 DOI: 10.1103/physrevlett.108.066810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Indexed: 05/31/2023]
Abstract
Resistively detected nuclear magnetic resonance is used to measure the Knight shift of the 75As nuclei and determine the electron spin polarization of the fractional quantum Hall states of the second Landau level. We show that the 5/2 state is fully polarized within experimental error, thus confirming a fundamental assumption of the Moore-Read theory. We measure the electron heating under radio frequency excitation and show that we are able to detect NMR at electron temperatures down to 30 mK.
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Affiliation(s)
- M Stern
- Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot, Israel.
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dos Santos LF, Gobato YG, Teodoro MD, Lopez-Richard V, Marques GE, Brasil MJSP, Orlita M, Kunc J, Maude DK, Henini M, Airey RJ. Circular polarization in a non-magnetic resonant tunneling device. Nanoscale Res Lett 2011; 6:101. [PMID: 21711613 PMCID: PMC3211145 DOI: 10.1186/1556-276x-6-101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 01/25/2011] [Indexed: 05/31/2023]
Abstract
We have investigated the polarization-resolved photoluminescence (PL) in an asymmetric n-type GaAs/AlAs/GaAlAs resonant tunneling diode under magnetic field parallel to the tunnel current. The quantum well (QW) PL presents strong circular polarization (values up to -70% at 19 T). The optical emission from GaAs contact layers shows evidence of highly spin-polarized two-dimensional electron and hole gases which affects the spin polarization of carriers in the QW. However, the circular polarization degree in the QW also depends on various other parameters, including the g-factors of the different layers, the density of carriers along the structure, and the Zeeman and Rashba effects.
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Affiliation(s)
- Lara F dos Santos
- Physics Department, Federal University of São Carlos, São Carlos, Brazil
| | - Yara Galvão Gobato
- Physics Department, Federal University of São Carlos, São Carlos, Brazil
| | - Márcio D Teodoro
- Physics Department, Federal University of São Carlos, São Carlos, Brazil
| | | | - Gilmar E Marques
- Physics Department, Federal University of São Carlos, São Carlos, Brazil
| | | | - Milan Orlita
- Grenoble High Magnet Field Laboratory, Grenoble, France
- Institute of Physics, Charles University, Ke Karlovu 5, 121 16 Praha 2, Czech Republic
| | - Jan Kunc
- Grenoble High Magnet Field Laboratory, Grenoble, France
- Institute of Physics, Charles University, Ke Karlovu 5, 121 16 Praha 2, Czech Republic
| | | | - Mohamed Henini
- School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Robert J Airey
- EPSRC National Centre for III-V Technologies, The University of Sheffield, Sheffield, UK
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Patanè A, Mori N, Makarovsky O, Eaves L, Zambrano ML, Arce JC, Dickinson L, Maude DK. Manipulating and imaging the shape of an electronic wave function by magnetotunneling spectroscopy. Phys Rev Lett 2010; 105:236804. [PMID: 21231494 DOI: 10.1103/physrevlett.105.236804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Indexed: 05/30/2023]
Abstract
We measure the current due to electrons tunneling through the ground state of hydrogenic Si donors placed in a GaAs quantum well in the presence of a magnetic field tilted at an angle to the plane of the well. The component of B parallel to the direction of current compresses the donor wave function. By measuring the current as a function of the perpendicular component of B, we probe how the magnetocompression affects the spatial form of the wave function and observe directly the transition from Coulombic to magnetic confinement at high fields.
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Affiliation(s)
- A Patanè
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
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40
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Stern M, Plochocka P, Umansky V, Maude DK, Potemski M, Bar-Joseph I. Optical probing of the spin polarization of the ν=5/2 quantum Hall state. Phys Rev Lett 2010; 105:096801. [PMID: 20868182 DOI: 10.1103/physrevlett.105.096801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Indexed: 05/29/2023]
Abstract
We apply polarization resolved photoluminescence spectroscopy to measure the spin polarization of a two dimensional electron gas in perpendicular magnetic field. We find that the splitting between the σ+ and σ- polarizations exhibits a sharp drop at ν=5/2 and is equal to the bare Zeeman energy, which resembles the behavior at even filling factors. We show that this behavior is consistent with filling factor ν=5/2 being unpolarized.
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Affiliation(s)
- M Stern
- Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot, Israel.
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41
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Orlita M, Faugeras C, Schneider JM, Martinez G, Maude DK, Potemski M. Graphite from the viewpoint of Landau level spectroscopy: an effective graphene bilayer and monolayer. Phys Rev Lett 2009; 102:166401. [PMID: 19518730 DOI: 10.1103/physrevlett.102.166401] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Indexed: 05/27/2023]
Abstract
We describe an infrared transmission study of a thin layer of bulk graphite in magnetic fields up to B=34 T. Two series of absorption lines whose energy scales as sqrt[B] and B are present in the spectra and identified as contributions of massless holes at the H point and massive electrons in the vicinity of the K point, respectively. We find that the optical response of the K point electrons corresponds, over a wide range of energy and magnetic field, to a graphene bilayer with an effective interlayer coupling 2gamma_{1}, twice the value for a real graphene bilayer, which reflects the crystal ordering of bulk graphite along the c axis. The K point electrons thus behave as massive Dirac fermions with a mass enhanced twice in comparison to a true graphene bilayer.
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Affiliation(s)
- M Orlita
- Laboratoire National des Champs Magnétiques Intenses, CNRS, BP 166, F-38042 Grenoble Cedex 09, France.
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42
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Schneider JM, Orlita M, Potemski M, Maude DK. Consistent interpretation of the low-temperature magnetotransport in graphite using the Slonczewski-Weiss-McClure 3D band-structure calculations. Phys Rev Lett 2009; 102:166403. [PMID: 19518732 DOI: 10.1103/physrevlett.102.166403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Indexed: 05/27/2023]
Abstract
Magnetotransport of natural graphite and highly oriented pyrolytic graphite has been measured at mK temperatures. Quantum oscillations for both electron and hole carriers are observed with an orbital angular momentum quantum number up to N approximately 90. A remarkable agreement is obtained when comparing the data and the predictions of the Slonczewski-Weiss-McClure tight binding model for massive fermions. No evidence for Dirac fermions is observed in the transport data which are dominated by the crossing of the Landau bands at the Fermi level, corresponding to dE/dk_{z}=0, which occurs away from the H point where Dirac fermions are expected.
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Affiliation(s)
- J M Schneider
- Grenoble High Magnetic Field Laboratory, CNRS, 38042 Grenoble, France.
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Plochocka P, Schneider JM, Maude DK, Potemski M, Rappaport M, Umansky V, Bar-Joseph I, Groshaus JG, Gallais Y, Pinczuk A. Optical absorption to probe the quantum Hall ferromagnet at filling factor nu=1. Phys Rev Lett 2009; 102:126806. [PMID: 19392309 DOI: 10.1103/physrevlett.102.126806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Indexed: 05/27/2023]
Abstract
Optical absorption measurements are used to probe the spin polarization in the integer and fractional quantum Hall effect regimes. The system is fully spin polarized only at filling factor nu=1 and at very low temperatures ( approximately 40 mK). A small change in filling factor (deltanu approximately +/-0.01) leads to a significant depolarization. This suggests that the itinerant quantum Hall ferromagnet at nu=1 is surprisingly fragile against increasing temperature, or against small changes in filling factor.
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Affiliation(s)
- P Plochocka
- Laboratoire National des Champs Magnétiques Intenses, Grenoble High Magnetic Field Laboratory, 38042 Grenoble, France.
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44
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Orlita M, Faugeras C, Plochocka P, Neugebauer P, Martinez G, Maude DK, Barra AL, Sprinkle M, Berger C, de Heer WA, Potemski M. Approaching the dirac point in high-mobility multilayer epitaxial graphene. Phys Rev Lett 2008; 101:267601. [PMID: 19437673 DOI: 10.1103/physrevlett.101.267601] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Multilayer epitaxial graphene is investigated using far infrared transmission experiments in the different limits of low magnetic fields and high temperatures. The cyclotron-resonance-like absorption is observed at low temperature in magnetic fields below 50 mT, probing the nearest vicinity of the Dirac point. The carrier mobility is found to exceed 250,000 cm2/(V x s). In the limit of high temperatures, the well-defined Landau level quantization is observed up to room temperature at magnetic fields below 1 T, a phenomenon unusual in solid state systems. A negligible increase in the width of the cyclotron resonance lines with increasing temperature indicates that no important scattering mechanism is thermally activated.
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Affiliation(s)
- M Orlita
- Grenoble High Magnetic Field Laboratory, CNRS, BP 166, F-38042 Grenoble Cedex 09, France.
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45
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Makarovsky O, Thomas O, Balanov AG, Eaves L, Patanè A, Campion RP, Foxon CT, Vdovin EE, Maude DK, Kiesslich G, Airey RJ. Fock-Darwin-like quantum dot states formed by charged Mn interstitial ions. Phys Rev Lett 2008; 101:226807. [PMID: 19113508 DOI: 10.1103/physrevlett.101.226807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Indexed: 05/27/2023]
Abstract
We report a method of creating electrostatically induced quantum dots by thermal diffusion of interstitial Mn ions out of a p-type (GaMn)As layer into the vicinity of a GaAs quantum well. This approach creates deep, approximately circular, and strongly confined dotlike potential minima in a large (200 microm) mesa diode structure without need for advanced lithography or electrostatic gating. Magnetotunneling spectroscopy of an individual dot reveals the symmetry of its electronic eigenfunctions and a rich energy level spectrum of Fock-Darwin-like states with an orbital angular momentum component |lz| from 0 to 11.
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Affiliation(s)
- O Makarovsky
- School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
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46
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Orlita M, Faugeras C, Martinez G, Maude DK, Sadowski ML, Potemski M. Dirac fermions at the H point of graphite: magnetotransmission studies. Phys Rev Lett 2008; 100:136403. [PMID: 18517976 DOI: 10.1103/physrevlett.100.136403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Indexed: 05/26/2023]
Abstract
We report on far infrared magnetotransmission measurements on a thin graphite sample prepared by exfoliation of highly oriented pyrolytic graphite. In a magnetic field, absorption lines exhibiting a blueshift proportional to sqrt[B] are observed. This is a fingerprint for massless Dirac holes at the H point in bulk graphite. The Fermi velocity is found to be c[over ] =( 1.02+/-0.02) x 10(6) m/s and the pseudogap |Delta| at the H point is estimated to be below 10 meV. Although the holes behave to a first approximation as a strictly 2D gas of Dirac fermions, the full 3D band structure has to be taken into account to explain all the observed spectral features.
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Affiliation(s)
- M Orlita
- Grenoble High Magnetic Field Laboratory, CNRS, BP 166, F-38042 Grenoble Cedex 09, France.
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47
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Takashina K, Brun M, Ota T, Maude DK, Fujiwara A, Ono Y, Takahashi Y, Hirayama Y. Anomalous resistance ridges along filling factor nu=4i. Phys Rev Lett 2007; 99:036803. [PMID: 17678309 DOI: 10.1103/physrevlett.99.036803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Indexed: 05/16/2023]
Abstract
We report anomalous structure in the magnetoresistance of SiO(2)/Si(100)/SiO(2) quantum wells. When Landau levels of opposite valleys are driven through coincidence at the Fermi level, the longitudinal resistance displays elevations at filling factors that are integer multiples of 4 (nu=4i) accompanied by suppression on either side of nu=4i. This persists when either the magnetic field or the valley splitting is swept, leading to resistance ridges running along nu=4i. The range of field over which they are observed points to the role of spin degeneracy, which is directly confirmed by their disappearance with the addition of an in-plane magnetic field. The data suggest a new type of many-body effect arising from the combined degeneracy due to the valley and the spin degrees of freedom.
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Affiliation(s)
- K Takashina
- NTT Basic Research Laboratories, NTT Corporation, Atsugi-shi, Kanagawa 243-0198, Japan
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48
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Allison G, Mori N, Patanè A, Endicott J, Eaves L, Maude DK, Hopkinson M. Strong effect of resonant impurities on Landau-level quantization. Phys Rev Lett 2006; 96:236802. [PMID: 16803389 DOI: 10.1103/physrevlett.96.236802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Indexed: 05/10/2023]
Abstract
We investigate experimentally the effect of a random distribution of nitrogen (N) impurities on the Landau-level spectrum of a GaAs quantum well. Our magnetotunneling study reveals complex and nonequally spaced Landau levels and a quenching of the Landau states at a well-defined bias and electron energy which is resonant with that of the N atoms. Analysis of the magnetic field dependence of the tunnel current into the Landau levels of the well also provides quantitative information about the nonresonant component of the N-related scattering potential.
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Affiliation(s)
- G Allison
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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49
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Könemann J, Haug RJ, Maude DK, Fal'ko VI, Altshuler BL. Spin-orbit coupling and anisotropy of spin splitting in quantum dots. Phys Rev Lett 2005; 94:226404. [PMID: 16090418 DOI: 10.1103/physrevlett.94.226404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Indexed: 05/03/2023]
Abstract
In lateral quantum dots, the combined effect of both Dresselhaus and Bychkov-Rashba spin-orbit coupling is equivalent to an effective magnetic field +/- B(SO) which has the opposite sign for s(z)= +/- 1/2 spin electrons. When the external magnetic field is perpendicular to the planar structure, the field B(SO) generates an additional splitting for electron states as compared to the spin splitting in the in-plane field orientation. The anisotropy of spin splitting has been measured and then analyzed in terms of spin-orbit coupling in several AlGaAs/GaAs quantum dots by means of resonant tunneling spectroscopy. From the measured values and sign of the anisotropy we are able to determine the dominating spin-orbit coupling mechanism.
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Affiliation(s)
- J Könemann
- Institut für Festkörperphysik, Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany
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Patanè A, Mori N, Fowler D, Eaves L, Henini M, Maude DK, Hamaguchi C, Airey R. Magnetic-field-induced suppression of electronic conduction in a superlattice. Phys Rev Lett 2004; 93:146801. [PMID: 15524824 DOI: 10.1103/physrevlett.93.146801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Indexed: 05/24/2023]
Abstract
We use a magnetic field applied along the axis of a semiconductor superlattice (SL) as a controllable means of creating a one-dimensional band structure. We demonstrate that the current flow through the SL is strongly suppressed when the electron motion perpendicular to the SL axis is strongly confined by the quantizing magnetic field. By modeling this behavior using semiclassical and nonequilibrium Green's function methods, we show that the observed quenching arises from a qualitative change in electron dynamics caused by increasing quantum confinement.
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Affiliation(s)
- A Patanè
- School of Physics and Astronomy, University of Nottingham, NG7 2RD, United Kingdom.
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