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Kipczak Ł, Karmakar A, Grzeszczyk M, Janiszewska R, Woźniak T, Chen Z, Pawłowski J, Watanabe K, Taniguchi T, Babiński A, Koperski M, Molas MR. Resonant Raman scattering of few layers CrBr 3. Sci Rep 2024; 14:7484. [PMID: 38553543 PMCID: PMC11350088 DOI: 10.1038/s41598-024-57622-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 03/20/2024] [Indexed: 08/20/2024] Open
Abstract
We investigate the vibrational and magnetic properties of thin layers of chromium tribromide (CrBr3) with a thickness ranging from three to twenty layers (3-20 L) revealed by the Raman scattering (RS) technique. Systematic dependence of the RS process efficiency on the energy of the laser excitation is explored for four different excitation energies: 1.96 eV, 2.21 eV, 2.41 eV, and 3.06 eV. Our characterization demonstrates that for 12 L CrBr3, 3.06 eV excitation could be considered resonant with interband electronic transitions due to the enhanced intensity of the Raman-active scattering resonances and the qualitative change in the Raman spectra. Polarization-resolved RS measurements for 12 L CrBr3 and first-principles calculations allow us to identify five observable phonon modes characterized by distinct symmetries, classified as the Ag and Eg modes. The evolution of phonon modes with temperature for a 16 L CrBr3 encapsulated in hexagonal boron nitride flakes demonstrates alterations of phonon energies and/or linewidths of resonances indicative of a transition between the paramagnetic and ferromagnetic state at Curie temperature (T C ≈ 50 K). The exploration of the effects of thickness on the phonon energies demonstrated small variations pronounces exclusively for the thinnest layers in the vicinity of 3-5 L. We propose that this observation can be due to the strong localization in the real space of interband electronic excitations, limiting the effects of confinement for resonantly excited Raman modes to atomically thin layers.
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Affiliation(s)
- Łucja Kipczak
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, 02-093, Warsaw, Poland.
| | - Arka Karmakar
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, 02-093, Warsaw, Poland
| | - Magdalena Grzeszczyk
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
| | - Róża Janiszewska
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370, Wrocław, Poland
| | - Tomasz Woźniak
- Faculty of Physics, Institute of Theoretical Physics, University of Warsaw, 02-093, Warsaw, Poland
| | - Zhaolong Chen
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- School of Advanced Materials, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
| | - Jan Pawłowski
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, 02-093, Warsaw, Poland
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Adam Babiński
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, 02-093, Warsaw, Poland
| | - Maciej Koperski
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Maciej R Molas
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, 02-093, Warsaw, Poland
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2
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Khanam S, Saikia S, Lee S, Park YB, Zaki MEA, Bania KK. Interfacial Effect-Induced Electrocatalytic Activity of Spinel Cobalt Oxide in Methanol Oxidation Reaction. ACS OMEGA 2023; 8:44964-44976. [PMID: 38046355 PMCID: PMC10688207 DOI: 10.1021/acsomega.3c06414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 12/05/2023]
Abstract
In this study, spinel cobalt oxide (Co3O4) nanoparticles without combining with any other metal atoms have been decorated through the influence of two hard templating agents, viz., zeolite-Y and carboxy-functionalized multiwalled carbon nanotubes (COOH-MWCNT). The adornment of the Co3O4 nanoparticles, through the combined impact of the aluminosilicate and carbon framework has resulted in quantum interference, causing the reversal of signatory Raman peaks of Co3O4. Apart from the construction of small Co3O4 nanoparticles at the interface of the two matrices, the particles were aligned along the direction of COOH-MWCNT. The catalyst Co3O4-Y-MWCNT exhibited excellent catalytic activity toward the methanol oxidation reaction (MOR) in comparison to Co3O4-Y, Co3O4-MWCNT, and bared Co3O4 with the current density of 0.92 A mg-1 at an onset potential of 1.33 V versus RHE. The material demonstrated persistent electrocatalytic activity up to 300 potential cycles and 20,000 s without substantial current density loss. High surface area of zeolite-Y in combination with the excellent conductivity of the COOH-MWCNT enhanced the electrocatalytic performance of the catalyst. The simplicity of synthesis, scale-up, and remarkable electrocatalytic activity of the catalyst Co3O4-Y-MWCNT provided an effective way toward the development of anode materials for direct methanol fuel cells.
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Affiliation(s)
- Salma
A. Khanam
- Department
of Chemical Sciences, Tezpur University, Tezpur 784028, Assam, India
| | - Sayanika Saikia
- Department
of Chemical Sciences, Tezpur University, Tezpur 784028, Assam, India
| | - Seonghwan Lee
- Department
of Mechanical Engineering, Ulsan National
Institute of Science and Technology, UNIST-gil 50, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Young-Bin Park
- Department
of Mechanical Engineering, Ulsan National
Institute of Science and Technology, UNIST-gil 50, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Magdi E. A. Zaki
- Department
of Chemistry, Imam Mohammad Ibn Saud Islamic
University (IMSIU), Riyadh 11623, Saudi Arabia
| | - Kusum K. Bania
- Department
of Chemical Sciences, Tezpur University, Tezpur 784028, Assam, India
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3
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Antoniazzi I, Zawadzka N, Grzeszczyk M, Woźniak T, Ibáñez J, Muhammad Z, Zhao W, Molas MR, Babiński A. The effect of temperature and excitation energy on Raman scattering in bulkHfS2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:305401. [PMID: 37072005 DOI: 10.1088/1361-648x/acce18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/18/2023] [Indexed: 06/19/2023]
Abstract
Raman scattering (RS) in bulk hafnium disulfide (HfS2) is investigated as a function of temperature (5 K - 350 K) with polarization resolution and excitation of several laser energies. An unexpected temperature dependence of the energies of the main Raman-active (A1gand Eg) modes with the temperature-induced blueshift in the low-temperature limit is observed. The low-temperature quenching of a modeω1(134 cm-1) and the emergence of a new mode at approx. 184 cm-1, labeledZ, is reported. The optical anisotropy of the RS inHfS2is also reported, which is highly susceptible to the excitation energy. The apparent quenching of the A1gmode atT = 5 K and of the Egmode atT= 300 K in the RS spectrum excited with 3.06 eV excitation is also observed. We discuss the results in the context of possible resonant character of light-phonon interactions. Analyzed is also a possible effect of the iodine molecules intercalated in the van der Waals gaps between neighboringHfS2layers, which inevitably result from the growth procedure.
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Affiliation(s)
- Igor Antoniazzi
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 02-093 Warsaw, Poland
| | - Natalia Zawadzka
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 02-093 Warsaw, Poland
| | - Magdalena Grzeszczyk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 02-093 Warsaw, Poland
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore 117544, Singapore
| | - Tomasz Woźniak
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27 50-370 Wrocław, Poland
| | - Jordi Ibáñez
- Geosciences Barcelona (GEO3BCN), CSIC, Lluís Solé i Sabarís s.n. 08028 Barcelona, Catalonia, Spain
| | - Zahir Muhammad
- Hefei Innovation Research Institute, School of Microelectronics, Beihang University, Hefei 230013, People's Republic of China
| | - Weisheng Zhao
- Hefei Innovation Research Institute, School of Microelectronics, Beihang University, Hefei 230013, People's Republic of China
| | - Maciej R Molas
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 02-093 Warsaw, Poland
| | - Adam Babiński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 02-093 Warsaw, Poland
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4
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Chen X, Reichardt S, Lin ML, Leng YC, Lu Y, Wu H, Mei R, Wirtz L, Zhang X, Ferrari AC, Tan PH. Control of Raman Scattering Quantum Interference Pathways in Graphene. ACS NANO 2023; 17:5956-5962. [PMID: 36897053 PMCID: PMC10062028 DOI: 10.1021/acsnano.3c00180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Graphene is an ideal platform to study the coherence of quantum interference pathways by tuning doping or laser excitation energy. The latter produces a Raman excitation profile that provides direct insight into the lifetimes of intermediate electronic excitations and, therefore, on quantum interference, which has so far remained elusive. Here, we control the Raman scattering pathways by tuning the laser excitation energy in graphene doped up to 1.05 eV. The Raman excitation profile of the G mode indicates its position and full width at half-maximum are linearly dependent on doping. Doping-enhanced electron-electron interactions dominate the lifetimes of Raman scattering pathways and reduce Raman interference. This will provide guidance for engineering quantum pathways for doped graphene, nanotubes, and topological insulators.
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Affiliation(s)
- Xue Chen
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center
of Materials Science and Optoelectronics Engineering and CAS Center
of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sven Reichardt
- Department
of Physics and Materials Science, University
of Luxembourg, Luxembourg 1511, Luxembourg
| | - Miao-Ling Lin
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Yu-Chen Leng
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Yan Lu
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Heng Wu
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center
of Materials Science and Optoelectronics Engineering and CAS Center
of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui Mei
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center
of Materials Science and Optoelectronics Engineering and CAS Center
of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ludger Wirtz
- Department
of Physics and Materials Science, University
of Luxembourg, Luxembourg 1511, Luxembourg
| | - Xin Zhang
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center
of Materials Science and Optoelectronics Engineering and CAS Center
of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Andrea C. Ferrari
- Cambridge
Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Ping-Heng Tan
- State
Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center
of Materials Science and Optoelectronics Engineering and CAS Center
of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
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5
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Bhatnagar M, Woźniak T, Kipczak Ł, Zawadzka N, Olkowska-Pucko K, Grzeszczyk M, Pawłowski J, Watanabe K, Taniguchi T, Babiński A, Molas MR. Temperature induced modulation of resonant Raman scattering in bilayer 2H-MoS 2. Sci Rep 2022; 12:14169. [PMID: 35986062 PMCID: PMC9391345 DOI: 10.1038/s41598-022-18439-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/11/2022] [Indexed: 11/15/2022] Open
Abstract
The temperature evolution of the resonant Raman scattering from high-quality bilayer 2H-MoS[Formula: see text] encapsulated in hexagonal BN flakes is presented. The observed resonant Raman scattering spectrum as initiated by the laser energy of 1.96 eV, close to the A excitonic resonance, shows rich and distinct vibrational features that are otherwise not observed in non-resonant scattering. The appearance of 1st and 2nd order phonon modes is unambiguously observed in a broad range of temperatures from 5 to 320 K. The spectrum includes the Raman-active modes, i.e. E[Formula: see text]([Formula: see text]) and A[Formula: see text]([Formula: see text]) along with their Davydov-split counterparts, i.e. E[Formula: see text]([Formula: see text]) and B[Formula: see text]([Formula: see text]). The temperature evolution of the Raman scattering spectrum brings forward key observations, as the integrated intensity profiles of different phonon modes show diverse trends. The Raman-active A[Formula: see text]([Formula: see text]) mode, which dominates the Raman scattering spectrum at T = 5 K quenches with increasing temperature. Surprisingly, at room temperature the B[Formula: see text]([Formula: see text]) mode, which is infrared-active in the bilayer, is substantially stronger than its nominally Raman-active A[Formula: see text]([Formula: see text]) counterpart.
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Affiliation(s)
- Mukul Bhatnagar
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland.
| | - Tomasz Woźniak
- Department of Semiconductor Materials Engineering, Wrocław University of Science and Technology, ul. Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Łucja Kipczak
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Natalia Zawadzka
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Katarzyna Olkowska-Pucko
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Magdalena Grzeszczyk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Jan Pawłowski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Adam Babiński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Maciej R Molas
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland.
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6
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Quantum interference directed chiral raman scattering in two-dimensional enantiomers. Nat Commun 2022; 13:1254. [PMID: 35273159 PMCID: PMC8913836 DOI: 10.1038/s41467-022-28877-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 02/16/2022] [Indexed: 12/04/2022] Open
Abstract
Raman scattering spectroscopy has been a necessary and accurate tool not only for characterizing lattice structure, but also for probing electron-photon and electron-phonon interactions. In the quantum picture, electrons at ground states can be excited to intermediate energy levels by photons at different k-points in the Brillouin zone, then couple to phonons and emit photons with changed energies. The elementary Raman processes via all possible pathways can interfere with each other, giving rise to intriguing scattering effects. Here we report that quantum interference can lead to significant chiral Raman response in monolayer transitional metal dichalcogenide with triclinic symmetry. Large circular intensity difference observed for monolayer rhenium dichalcogenide originates from inter-k interference of Raman scattering excited by circularly polarized light with opposite helicities. Our results reveal chiral Raman spectra as a new manifestation of quantum interference in Raman scattering process, and may inspire induction of chiral optical response in other materials. Quantum interference among elementary Raman processes has only been observed in few materials under specific excitation configurations. Here, the authors show that quantum interference can lead to significant chiral Raman response in a monolayer material of transitional metal dichalcogenide with triclinic symmetry.
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7
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Resonance and antiresonance in Raman scattering in GaSe and InSe crystals. Sci Rep 2021; 11:924. [PMID: 33441595 PMCID: PMC7806833 DOI: 10.1038/s41598-020-79411-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/02/2020] [Indexed: 11/08/2022] Open
Abstract
The temperature effect on the Raman scattering efficiency is investigated in [Formula: see text]-GaSe and [Formula: see text]-InSe crystals. We found that varying the temperature over a broad range from 5 to 350 K permits to achieve both the resonant conditions and the antiresonance behaviour in Raman scattering of the studied materials. The resonant conditions of Raman scattering are observed at about 270 K under the 1.96 eV excitation for GaSe due to the energy proximity of the optical band gap. In the case of InSe, the resonant Raman spectra are apparent at about 50 and 270 K under correspondingly the 2.41 eV and 2.54 eV excitations as a result of the energy proximity of the so-called B transition. Interestingly, the observed resonances for both materials are followed by an antiresonance behaviour noticeable at higher temperatures than the detected resonances. The significant variations of phonon-modes intensities can be explained in terms of electron-phonon coupling and quantum interference of contributions from different points of the Brillouin zone.
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8
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Reichardt S, Wirtz L. Nonadiabatic exciton-phonon coupling in Raman spectroscopy of layered materials. SCIENCE ADVANCES 2020; 6:eabb5915. [PMID: 32821840 PMCID: PMC7413722 DOI: 10.1126/sciadv.abb5915] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/26/2020] [Indexed: 05/25/2023]
Abstract
We present an ab initio computational approach for the calculation of resonant Raman intensities, including both excitonic and nonadiabatic effects. Our diagrammatic approach, which we apply to two prototype, semiconducting layered materials, allows a detailed analysis of the impact of phonon-mediated exciton-exciton scattering on the intensities. In the case of bulk hexagonal boron nitride, this scattering leads to strong quantum interference between different excitonic resonances, strongly redistributing oscillator strength with respect to optical absorption spectra. In the case of MoS2, we observe that quantum interference effects are suppressed by the spin-orbit splitting of the excitons.
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9
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Trovatello C, Miranda HPC, Molina-Sánchez A, Borrego-Varillas R, Manzoni C, Moretti L, Ganzer L, Maiuri M, Wang J, Dumcenco D, Kis A, Wirtz L, Marini A, Soavi G, Ferrari AC, Cerullo G, Sangalli D, Conte SD. Strongly Coupled Coherent Phonons in Single-Layer MoS 2. ACS NANO 2020; 14:5700-5710. [PMID: 32233453 DOI: 10.1021/acsnano.0c00309] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We present a transient absorption setup combining broadband detection over the visible-UV range with high temporal resolution (∼20 fs) which is ideally suited to trigger and detect vibrational coherences in different classes of materials. We generate and detect coherent phonons (CPs) in single-layer (1L)-MoS2, as a representative semiconducting 1L-transition metal dichalcogenide (TMD), where the confined dynamical interaction between excitons and phonons is unexplored. The coherent oscillatory motion of the out-of-plane A'1 phonons, triggered by the ultrashort laser pulses, dynamically modulates the excitonic resonances on a time scale of few tens of fs. We observe an enhancement by almost 2 orders of magnitude of the CP amplitude when detected in resonance with the C exciton peak, combined with a resonant enhancement of CP generation efficiency. Ab initio calculations of the change in the 1L-MoS2 band structure induced by the A'1 phonon displacement confirm a strong coupling with the C exciton. The resonant behavior of the CP amplitude follows the same spectral profile of the calculated Raman susceptibility tensor. These results explain the CP generation process in 1L-TMDs and demonstrate that CP excitation in 1L-MoS2 can be described as a Raman-like scattering process.
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Affiliation(s)
- Chiara Trovatello
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Henrique P C Miranda
- Institute of Condensed Matter and Nanoscience (IMCN), Université Catholique de Louvain, B-1348 Louvain-laneuve, Belgium
| | - Alejandro Molina-Sánchez
- Institute of Materials Science (ICMUV), University of Valencia, Catedrático Beltrán 2, E-46980 Valencia, Spain
| | - Rocío Borrego-Varillas
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | | | - Luca Moretti
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Lucia Ganzer
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Margherita Maiuri
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Junjia Wang
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Dumitru Dumcenco
- Electrical Engineering Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Andras Kis
- Electrical Engineering Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Ludger Wirtz
- Université du Luxembourg, 162 A, avenue de la Faencerie, Luxembourg City L-1511, Luxembourg
| | - Andrea Marini
- Division of Ultrafast Process in Materials (FLASHit), CNR-ISM, Area della Ricerca di Roma 1, 00016 Monterotondo Scalo, Italy
| | - Giancarlo Soavi
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
- IFN-CNR, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Davide Sangalli
- Division of Ultrafast Process in Materials (FLASHit), CNR-ISM, Area della Ricerca di Roma 1, 00016 Monterotondo Scalo, Italy
| | - Stefano Dal Conte
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
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10
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Giegold V, Lange L, Ciesielski R, Hartschuh A. Non-linear Raman scattering intensities in graphene. NANOSCALE 2020; 12:5612-5617. [PMID: 32100772 DOI: 10.1039/c9nr10654e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We show that the Raman scattering signals of the two dominant Raman bands G and 2D of graphene sensitively depend on the laser intensity in opposite ways. High electronic temperatures reached for pulsed laser excitation lead to an asymmetric Fermi-Dirac distribution at the different optically resonant states contributing to Raman scattering. This results in a partial Pauli blocking of destructively interfering quantum pathways for G band scattering, which is observed as a super-linear increase of the G band intensity with laser power. The 2D band, on the other hand, exhibits sub-linear intensity scaling due to the blocking of constructively interfering contributions. The opposite intensity dependencies of the two bands are found to reduce the observed 2D/G ratio, a key quantity used for characterizing graphene samples, by more than factor two for electronic temperatures around 3000 K.
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Affiliation(s)
- Veit Giegold
- Department of Chemistry and Center for NanoScience (CeNS), LMU Munich, Butenandtstr. 5-13, 81377 Munich, Germany.
| | - Lucas Lange
- Department of Chemistry and Center for NanoScience (CeNS), LMU Munich, Butenandtstr. 5-13, 81377 Munich, Germany.
| | - Richard Ciesielski
- Department of Chemistry and Center for NanoScience (CeNS), LMU Munich, Butenandtstr. 5-13, 81377 Munich, Germany.
| | - Achim Hartschuh
- Department of Chemistry and Center for NanoScience (CeNS), LMU Munich, Butenandtstr. 5-13, 81377 Munich, Germany.
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11
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Park M, Choi JS, Yang L, Lee H. Raman Spectra Shift of Few-Layer IV-VI 2D Materials. Sci Rep 2019; 9:19826. [PMID: 31863038 PMCID: PMC6925276 DOI: 10.1038/s41598-019-55577-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 11/21/2019] [Indexed: 11/08/2022] Open
Abstract
Raman spectroscopy is the most commonly used method to investigate structures of materials. Recently, few-layered IV-VI 2D materials (SnS, SnSe, GeS, and GeSe) have been found and ignited significant interest in electronic and optical applications. However, unlike few-layer graphene, in which its interlayer structures such as the number of its layers are confirmed through measurement of the Raman scattering, few-layer IV-VI 2D materials have not yet been developed to the point of understanding their interlayer structure. Here we performed first-principles calculations on Raman spectroscopy for few-layer IV-VI 2D materials. In addition to achieving consistent results with measurements of bulk structures, we revealed significant red and blue shifts of characteristic Raman modes up to 100 cm-1 associated with the layer number. These shifts of lattice vibrational modes originate from the change of the bond lengths between the metal atoms and chalcogen atoms through the change of the interlayer interactions. Particularly, our study shows weak covalent bonding between interlayers, making the evolution of Raman signals according to the thickness different from other vdW materials. Our results suggest a new way for obtaining information of layer structure of few-layer IV-VI 2D materials through Raman spectroscopy.
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Affiliation(s)
- Minwoo Park
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri, 63136, USA
- Department of Physics, Konkuk University, Seoul, 05029, Korea
| | - Jin Sik Choi
- Department of Physics, Konkuk University, Seoul, 05029, Korea
| | - Li Yang
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri, 63136, USA.
| | - Hoonkyung Lee
- Department of Physics, Konkuk University, Seoul, 05029, Korea.
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12
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Elalfy L, Music D, Hu M. First Principles Investigation of Anomalous Pressure-Dependent Thermal Conductivity of Chalcopyrites. MATERIALS 2019; 12:ma12213491. [PMID: 31731398 PMCID: PMC6862127 DOI: 10.3390/ma12213491] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/11/2019] [Accepted: 10/23/2019] [Indexed: 11/16/2022]
Abstract
The effect of compression on the thermal conductivity of CuGaS2, CuInS2, CuInTe2, and AgInTe2 chalcopyrites (space group I-42d) was studied at 300 K using phonon Boltzmann transport equation (BTE) calculations. The thermal conductivity was evaluated by solving the BTE with harmonic and third-order interatomic force constants. The thermal conductivity of CuGaS2 increases with pressure, which is a common behavior. Striking differences occur for the other three compounds. CuInTe2 and AgInTe2 exhibit a drop in the thermal conductivity upon increasing pressure, which is anomalous. AgInTe2 reaches a very low thermal conductivity of 0.2 W·m-1·K-1 at 2.6 GPa, being beneficial for many energy devices, such as thermoelectrics. CuInS2 is an intermediate case. Based on the phonon dispersion data, the phonon frequencies of the acoustic modes for CuInTe2 and AgInTe2 decrease with increasing pressure, thereby driving the anomaly, while there is no significant pressure effect for CuGaS2. This leads to the negative Grüneisen parameter for CuInTe2 and AgInTe2, a decreased phonon relaxation time, and a decreased thermal conductivity. This softening of the acoustic modes upon compression is suggested to be due to a rotational motion of the chalcopyrite building blocks rather than a compressive oscillation. The negative Grüneisen parameters and the anomalous phonon behavior yield a negative thermal expansion coefficient at lower temperatures, based on the Grüneisen vibrational theory.
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Affiliation(s)
- Loay Elalfy
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany;
- Correspondence: (L.E.); (M.H.)
| | - Denis Music
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany;
| | - Ming Hu
- Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208, USA
- Correspondence: (L.E.); (M.H.)
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13
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Li A, Chen Q, Wang P, Gan Y, Qi T, Wang P, Tang F, Wu JZ, Chen R, Zhang L, Gong Y. Ultrahigh-Sensitive Broadband Photodetectors Based on Dielectric Shielded MoTe 2 /Graphene/SnS 2 p-g-n Junctions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805656. [PMID: 30549329 DOI: 10.1002/adma.201805656] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/26/2018] [Indexed: 05/23/2023]
Abstract
2D atomic sheets of transition metal dichalcogenides (TMDs) have a tremendous potential for next-generation optoelectronics since they can be stacked layer-by-layer to form van der Waals (vdW) heterostructures. This allows not only bypassing difficulties in heteroepitaxy of lattice-mismatched semiconductors of desired functionalities but also providing a scheme to design new optoelectronics that can surpass the fundamental limitations on their conventional semiconductor counterparts. Herein, a novel 2D h-BN/p-MoTe2 /graphene/n-SnS2 /h-BN p-g-n junction, fabricated by a layer-by-layer dry transfer, demonstrates high-sensitivity, broadband photodetection at room temperature. The combination of the MoTe2 and SnS2 of complementary bandgaps, and the graphene interlayer provides a unique vdW heterostructure with a vertical built-in electric field for high-efficiency broadband light absorption, exciton dissociation, and carrier transfer. The graphene interlayer plays a critical role in enhancing sensitivity and broadening the spectral range. An optimized device containing 5-7-layer graphene has been achieved and shows an extraordinary responsivity exceeding 2600 A W-1 with fast photoresponse and specific detectivity up to ≈1013 Jones in the ultraviolet-visible-near-infrared spectrum. This result suggests that the vdW p-g-n junctions containing multiple photoactive TMDs can provide a viable approach toward future ultrahigh-sensitivity and broadband photonic detectors.
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Affiliation(s)
- Alei Li
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Physics, Harbin Institute of Technology, Harbin, 150001, China
| | - Qianxue Chen
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Peipei Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yuan Gan
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Tailei Qi
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Peng Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Fangdong Tang
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Judy Z Wu
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, 66045, USA
| | - Rui Chen
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Liyuan Zhang
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Youpin Gong
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
- SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518055, China
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14
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Grzeszczyk M, Gołasa K, Molas MR, Nogajewski K, Zinkiewicz M, Potemski M, Wysmołek A, Babiński A. Raman scattering from the bulk inactive out-of-plane [Formula: see text] mode in few-layer MoTe 2. Sci Rep 2018; 8:17745. [PMID: 30531971 PMCID: PMC6288152 DOI: 10.1038/s41598-018-35510-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/05/2018] [Indexed: 11/17/2022] Open
Abstract
We report a study of Raman scattering in few-layer MoTe2 focused on high-frequency out-of-plane vibrational modes near 291 cm-1 which are associated with the bulk-inactive [Formula: see text] mode. Our temperature-dependent measurements reveal a double peak structure of the feature related to these modes in the Raman scattering spectra of 4- and 5-layer MoTe2. In accordance with literature data, the doublet's lower- and higher-energy components are ascribed to the Raman-active A1g/[Formula: see text] vibrations involving, respectively, only the inner and surface layers. We demonstrate a strong enhancement of the inner mode's intensity at low temperature for 1.91 eV and 1.96 eV laser light excitation which suggests a resonant character of the Raman scattering processes probed under such conditions. A resonance of the laser light with a singularity of the electronic density of states at the M point of the MoTe2 Brillouin zone is proposed to be responsible for the observed effects.
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Affiliation(s)
- M. Grzeszczyk
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - K. Gołasa
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - M. R. Molas
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 25, Avenue des Martyrs, 38042 Grenoble, France
| | - K. Nogajewski
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 25, Avenue des Martyrs, 38042 Grenoble, France
| | - M. Zinkiewicz
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - M. Potemski
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 25, Avenue des Martyrs, 38042 Grenoble, France
| | - A. Wysmołek
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - A. Babiński
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
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15
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Liu HL, Yang T, Tatsumi Y, Zhang Y, Dong B, Guo H, Zhang Z, Kumamoto Y, Li MY, Li LJ, Saito R, Kawata S. Deep-ultraviolet Raman scattering spectroscopy of monolayer WS 2. Sci Rep 2018; 8:11398. [PMID: 30061708 PMCID: PMC6065453 DOI: 10.1038/s41598-018-29587-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/09/2018] [Indexed: 11/08/2022] Open
Abstract
Raman scattering measurements of monolayer WS2 are reported as a function of the laser excitation energies from the near-infrared (1.58 eV) to the deep-ultraviolet (4.82 eV). In particular, we observed several strong Raman peaks in the range of 700∼850 cm-1 with the deep-ultraviolet laser lights (4.66 eV and 4.82 eV). Using the first-principles calculations, these peaks and other weak peaks were appropriately assigned by the double resonance Raman scattering spectra of phonons around the M and K points in the hexagonal Brillouin zone. The relative intensity of the first-order [Formula: see text] to A1g peak changes dramatically with the 1.58 eV and 2.33 eV laser excitations, while the comparable relative intensity was observed for other laser energies. The disappearance of the [Formula: see text] peak with the 1.58 eV laser light comes from the fact that valley polarization of the laser light surpasses the [Formula: see text] mode since the [Formula: see text] mode is the helicity-exchange Raman mode. On the other hand, the disappearance of the A1g peak with the 2.33 eV laser light might be due to the strain effect on the electron-phonon matrix element.
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Affiliation(s)
- Hsiang-Lin Liu
- Department of Physics, National Taiwan Normal University, Taipei, 11677, Taiwan.
| | - Teng Yang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China.
- Department of Physics, Tohoku University, Sendai, 980-8578, Japan.
| | - Yuki Tatsumi
- Department of Physics, Tohoku University, Sendai, 980-8578, Japan
| | - Ye Zhang
- College of Sciences, Liaoning Shihua University, Fushun, 113001, China
| | - Baojuan Dong
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China
| | - Huaihong Guo
- Department of Physics, Tohoku University, Sendai, 980-8578, Japan
- College of Sciences, Liaoning Shihua University, Fushun, 113001, China
| | - Zhidong Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China
| | - Yasuaki Kumamoto
- Department of Applied Physics, Osaka University 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Pathology and Cell Regulation, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Ming-Yang Li
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
- Research Center for Applied Science, Academia Sinica, Taipei, 10617, Taiwan
| | - Lain-Jong Li
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Riichiro Saito
- Department of Physics, Tohoku University, Sendai, 980-8578, Japan
| | - Satoshi Kawata
- Department of Applied Physics, Osaka University 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
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16
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Qian Q, Zhang Z, Chen KJ. In Situ Resonant Raman Spectroscopy to Monitor the Surface Functionalization of MoS 2 and WSe 2 for High-k Integration: A First-Principles Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2882-2889. [PMID: 29400978 DOI: 10.1021/acs.langmuir.7b03840] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Surface functionalization of the dangling-bond-free MoS2, WSe2, and other TMDs (transition metal dichalcogenides) is of large practical importance, for example, in providing nucleation sites for the subsequent high-k dielectric integration. Of the surface functionalization methods, the reversible O or N atom adsorption on top of the chalcogen atoms is most promising. However, hazards such as severe oxidation or nitridation persist when the adsorption coverage is high. An in situ characterization technique, which can be integrated with the surface functionalization and dielectric deposition chamber, becomes valuable to enable the real-time monitoring of surface adsorption conditions. Raman spectroscopy, as a nondestructive characterization method without vacuum requirement, is a strong candidate. By utilizing first-principles calculations, Raman spectra of single-layer MoS2 and WSe2 with various O/N adsorption coverages are studied. The calculations suggest that the low-coverage O/N adsorbates will act as perturbations to the periodic lattice and activate the acoustic-phonon Raman scatterings. While high-coverage adsorptions will further activate and intensify the optical-phonon Raman scatterings of previously silent A2u and E1g modes, due to the breaking of reflection symmetry in the z direction, new phonon modes associated with the adatom oscillations are also introduced. All these pieces of evidence, together with the peak shifts of previously active A1g and E2g1 modes, suggest that in situ resonant Raman spectroscopy is capable of providing important information to quantify the O/N adsorption coverage and can be used as a valuable real-time characterization technique to monitor and control the surface functionalization conditions of MoS2 and WSe2.
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Affiliation(s)
- Qingkai Qian
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong SAR, China
| | - Zhaofu Zhang
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong SAR, China
| | - Kevin J Chen
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong SAR, China
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17
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Liang L, Zhang J, Sumpter BG, Tan QH, Tan PH, Meunier V. Low-Frequency Shear and Layer-Breathing Modes in Raman Scattering of Two-Dimensional Materials. ACS NANO 2017; 11:11777-11802. [PMID: 29099577 DOI: 10.1021/acsnano.7b06551] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ever since the isolation of single-layer graphene in 2004, two-dimensional layered structures have been among the most extensively studied classes of materials. To date, the pool of two-dimensional materials (2DMs) continues to grow at an accelerated pace and already covers an extensive range of fascinating and technologically relevant properties. An array of experimental techniques have been developed and used to characterize and understand these properties. In particular, Raman spectroscopy has proven to be a key experimental technique, thanks to its capability to identify minute structural and electronic effects in nondestructive measurements. While high-frequency (HF) intralayer Raman modes have been extensively employed for 2DMs, recent experimental and theoretical progress has demonstrated that low-frequency (LF) interlayer Raman modes are more effective at determining layer numbers and stacking configurations and provide a unique opportunity to study interlayer coupling. These advantages are due to 2DMs' unique interlayer vibration patterns where each layer behaves as an almost rigidly moving object with restoring forces corresponding to weak interlayer interactions. Compared to HF Raman modes, the relatively small attention originally devoted to LF Raman modes is largely due to their weaker signal and their proximity to the strong Rayleigh line background, which previously made their detection challenging. Recent progress in Raman spectroscopy with technical and hardware upgrades now makes it possible to probe LF modes with a standard single-stage Raman system and has proven crucial to characterize and understand properties of 2DMs. Here, we present a comprehensive and forward-looking review on the current status of exploiting LF Raman modes of 2DMs from both experimental and theoretical perspectives, revealing the fundamental physics and technological significance of LF Raman modes in advancing the field of 2DMs. We review a broad array of materials, with varying thickness and stacking configurations, discuss the effect of in-plane anisotropy, and present a generalized linear chain model and interlayer bond polarizability model to rationalize the experimental findings. We also discuss the instrumental improvements of Raman spectroscopy to enhance and separate LF Raman signals from the Rayleigh line. Finally, we highlight the opportunities and challenges ahead in this fast-developing field.
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Affiliation(s)
- Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Jun Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, China
- CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences , Beijing 100190, China
| | - Bobby G Sumpter
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Qing-Hai Tan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, China
- CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences , Beijing 100190, China
| | - Ping-Heng Tan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, China
- CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences , Beijing 100190, China
| | - Vincent Meunier
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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