1
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Liu Q, Lu X, Liu Y, Li Z, Yan P, Chen W, Meng Q, Zhang Y, Yam C, He L, Yan Y, Zhang Y, Wu J, Frauenheim T, Zhang R, Xu Y. Carrier Relaxation and Multiplication in Bi Doped Graphene. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206218. [PMID: 36670078 DOI: 10.1002/smll.202206218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/09/2023] [Indexed: 05/04/2023]
Abstract
By introducing different contents of Bi adatoms to the surface of monolayer graphene, the carrier concentration and their dynamics have been effectively modulated as probed directly by the time- and angle-resolved photoemission spectroscopy technique. The Bi adatoms are found to assist acoustic phonon scattering events mediated by supercollisions as the disorder effectively relaxes the momentum conservation constraint. A reduced carrier multiplication has been observed, which is related to the shrinking Fermi sea for scattering, as confirmed by time-dependent density functional theory simulation. This work gives insight into hot carrier dynamics in graphene, which is crucial for promoting the application of photoelectric devices.
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Affiliation(s)
- Qi Liu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Xianyang Lu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yuxiang Liu
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 28359, Bremen, Germany
| | - Zhihao Li
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Pengfei Yan
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Wang Chen
- National Laboratory of Solid State Microstructure, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Qinghao Meng
- National Laboratory of Solid State Microstructure, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Yongheng Zhang
- National Laboratory of Solid State Microstructure, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - ChiYung Yam
- Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen, 518000, China
- Hong Kong Quantum AI Lab Limited, Hong Kong, 00000, China
| | - Liang He
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yu Yan
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yi Zhang
- National Laboratory of Solid State Microstructure, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Jing Wu
- York-Nanjing Joint Center (YNJC) for Spintronics and Nano-engineering, Department of Electronics and Physics, University of York, York, YO10 5DD, UK
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 28359, Bremen, Germany
- Beijing Computational Science Research Center, Haidian District, Beijing, 100193, China
- Shenzhen JL Computational Science and Applied Research Institute, Shenzhen, 518109, China
| | - Rong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yongbing Xu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
- York-Nanjing Joint Center (YNJC) for Spintronics and Nano-engineering, Department of Electronics and Physics, University of York, York, YO10 5DD, UK
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2
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Sharma S, Myers-Ward RL, Gaskill KD, Chatzakis I. Ultrafast hot-carrier cooling in quasi freestanding bilayer graphene with hydrogen intercalated atoms. NANOSCALE ADVANCES 2023; 5:485-492. [PMID: 36756263 PMCID: PMC9846464 DOI: 10.1039/d2na00678b] [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: 10/02/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Femtosecond-THz optical pump probe spectroscopy is employed to investigate the cooling dynamics of hot carriers in quasi-free standing bilayer epitaxial graphene with hydrogen interacalation. We observe longer decay time constants, in the range of 2.6 to 6.4 ps, compared to previous studies on monolayer graphene, which increase nonlinearly with excitation intensity. The increased relaxation times are due to the decoupling of the graphene layer from the SiC substrate after hydrogen intercalation which increases the distance between graphene and substrate. Furthermore, our measurements show that the supercollision mechanism is not related to the cooling process of the hot carriers, which is ultimately achieved by electron optical phonon scattering.
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Affiliation(s)
- Sachin Sharma
- Texas Tech University Department of Physics & Astronomy Lubbock Texas TX 79409 USA
| | | | - Kurt D Gaskill
- Institute for Research in Electronics and Applied Physics, University of Maryland College Park MD USA
| | - Ioannis Chatzakis
- Texas Tech University Department of Physics & Astronomy Lubbock Texas TX 79409 USA
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3
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Vella D, Mrzel A, Drnovšek A, Shvalya V, Jezeršek M. Ultrasonic photoacoustic emitter of graphene-nanocomposites film on a flexible substrate. PHOTOACOUSTICS 2022; 28:100413. [PMID: 36276232 PMCID: PMC9579491 DOI: 10.1016/j.pacs.2022.100413] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/16/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Photoacoustic devices generating high-amplitude and high-frequency ultrasounds are attractive candidates for medical therapies and on-chip bio-applications. Here, we report the photoacoustic response of graphene nanoflakes - Polydimethylsiloxane composite. A protocol was developed to obtain well-dispersed graphene into the polymer, without the need for surface functionalization, at different weight percentages successively spin-coated onto a Polydimethylsiloxane substrate. We found that the photoacoustic amplitude scales up with optical absorption reaching 11 MPa at ∼ 228 mJ/cm2 laser fluence. We observed a deviation of the pressure amplitude from the linearity increasing the laser fluence, which indicates a decrease of the Grüneisen parameter. Spatial confinement of high amplitude (> 40 MPa, laser fluence > 55 mJ/cm2) and high frequency (Bw-6db ∼ 21.5 MHz) ultrasound was achieved by embedding the freestanding film in an optical lens. The acoustic gain promotes the formation of cavitation microbubbles for moderate fluence in water and in tissue-mimicking material. Our results pave the way for novel photoacoustic medical devices and integrated components.
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Affiliation(s)
- Daniele Vella
- Faculty of Mechanical Engineering, Laboratory for Laser Techniques, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia
| | - Aleš Mrzel
- Jožef Stefan Institute, Department of Complex Matter, Jamova 39, 1000 Ljubljana, Slovenia
| | - Aljaž Drnovšek
- Jožef Stefan Institute, Department of Thin Films and Surfaces, Jamova 39, 1000 Ljubljana, Slovenia
| | - Vasyl Shvalya
- Jožef Stefan Institute, Department of Gaseous Electronic, Jamova 39, 1000 Ljubljana, Slovenia
| | - Matija Jezeršek
- Faculty of Mechanical Engineering, Laboratory for Laser Techniques, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia
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4
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Liu H, Wang J, Liu Y, Wang Y, Xu L, Huang L, Liu D, Luo J. Visualizing Ultrafast Defect-Controlled Interlayer Electron-Phonon Coupling in Van der Waals Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106955. [PMID: 35474352 DOI: 10.1002/adma.202106955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 03/19/2022] [Indexed: 06/14/2023]
Abstract
Engineering ultrafast interlayer coupling provides access to new quantum phenomena and novel device functionalities in atomically thin van der Waals heterostructures. However, due to all the atoms of a monolayer material being exposed at the interfaces, the interlayer coupling is extremely susceptible to defects, resulting in high energy dissipation through heat and low device performance. The study of how defects affect the interlayer coupling at ultrafast and atomic scales remains a challenge. Here, using femtosecond transient absorption microscopy, a new defect-induced ultrafast interlayer electron-phonon coupling pathway is identified in a WS2 /graphene heterostructure, involving a three-body collision between electrons in WS2 and both acoustic phonons and defects in graphene. This interaction manifests as the reduced defect-related Raman resonant activity and the accelerated electron-phonon scattering time from 7.1 to 2.4 ps. Furthermore, the ultrafast interlayer coupling process is directly imaged. These insights will advance the fundamental knowledge of heat dissipation in nanoscale devices, and enable new ways to dynamically manipulate electrons and phonons via defects in van der Waals heterostructures.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China
| | - Jiangcai Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China
| | - Yuanshuang Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China
| | - Yong Wang
- Research Center for Quantum Optics and Quantum Communication, School of Science, Qingdao University of Technology, Qingdao, 266525, China
| | - Lujie Xu
- School of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University, Beijing, 100192, China
| | - Li Huang
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China
| | - Dameng Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China
| | - Jianbin Luo
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China
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5
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Pogna EA, Tomadin A, Balci O, Soavi G, Paradisanos I, Guizzardi M, Pedrinazzi P, Mignuzzi S, Tielrooij KJ, Polini M, Ferrari AC, Cerullo G. Electrically Tunable Nonequilibrium Optical Response of Graphene. ACS NANO 2022; 16:3613-3624. [PMID: 35188753 PMCID: PMC9098177 DOI: 10.1021/acsnano.1c04937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
The ability to tune the optical response of a material via electrostatic gating is crucial for optoelectronic applications, such as electro-optic modulators, saturable absorbers, optical limiters, photodetectors, and transparent electrodes. The band structure of single layer graphene (SLG), with zero-gap, linearly dispersive conduction and valence bands, enables an easy control of the Fermi energy, EF, and of the threshold for interband optical absorption. Here, we report the tunability of the SLG nonequilibrium optical response in the near-infrared (1000-1700 nm/0.729-1.240 eV), exploring a range of EF from -650 to 250 meV by ionic liquid gating. As EF increases from the Dirac point to the threshold for Pauli blocking of interband absorption, we observe a slow-down of the photobleaching relaxation dynamics, which we attribute to the quenching of optical phonon emission from photoexcited charge carriers. For EF exceeding the Pauli blocking threshold, photobleaching eventually turns into photoinduced absorption, because the hot electrons' excitation increases the SLG absorption. The ability to control both recovery time and sign of the nonequilibrium optical response by electrostatic gating makes SLG ideal for tunable saturable absorbers with controlled dynamics.
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Affiliation(s)
- Eva A.
A. Pogna
- NEST,
Istituto Nanoscienze-CNR and Scuola Normale Superiore, 56127 Pisa, Italy
- Dipartimento
di Fisica, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Andrea Tomadin
- Dipartimento
di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
| | - Osman Balci
- Cambridge
Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K.
| | - Giancarlo Soavi
- Cambridge
Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K.
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Jena 07743, Germany
| | - Ioannis Paradisanos
- Cambridge
Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K.
| | - Michele Guizzardi
- Dipartimento
di Fisica, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Paolo Pedrinazzi
- L-NESS,
Department of Physics, Politecnico di Milano, Via Anzani 42, Como 22100, Italy
| | - Sandro Mignuzzi
- Cambridge
Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K.
| | - Klaas-Jan Tielrooij
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), BIST & CSIC, Campus UAB, Bellaterra, Barcelona 08193, Spain
| | - Marco Polini
- Dipartimento
di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
- Istituto
Italiano di Tecnologia, Graphene Laboratories, Via Morego 30, 16163 Genova, Italy
| | - Andrea C. Ferrari
- Cambridge
Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K.
| | - Giulio Cerullo
- Dipartimento
di Fisica, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy
- Istituto
di Fotonica e Nanotecnologie, Consiglio
Nazionale delle Ricerche, Piazza L. da Vinci 32, 20133 Milano, Italy
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6
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Huo CF, Wen R, Yan XQ, Li DK, Huang KX, Zhu Y, Cui Q, Xu C, Liu ZB, Tian JG. Thickness-dependent ultrafast charge-carrier dynamics and coherent acoustic phonon oscillations in mechanically exfoliated PdSe 2 flakes. Phys Chem Chem Phys 2021; 23:20666-20674. [PMID: 34515274 DOI: 10.1039/d1cp03202j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recently, palladium diselenide (PdSe2) has emerged as a promising material with potential applications in electronic and optoelectronic devices due to its intriguing electronic and optical properties. The performance of the device is strongly dependent on the charge-carrier dynamics and the related hot phonon behavior. Here, we investigate the photoexcited-carrier dynamics and coherent acoustic phonon (CAP) oscillations in mechanically exfoliated PdSe2 flakes with a thickness ranging from 10.6 nm to 54 nm using time-resolved non-degenerate pump-probe transient reflection (TR) spectroscopy. The results imply that the CAP frequency is thickness-dependent. Polarization-resolved transient reflection (PRTR) measurements reveal the isotropic charge-carrier relaxation dynamics and the CAP frequency in the 10.6 nm region. In addition, the deformation potential (DP) mechanism dominates the generation of the CAP. Moreover, a sound velocity of 6.78 × 103 m s-1 is extracted from the variation of the oscillation period with the flake thickness and the delay time of the acoustic echo. These results provide insight into the ultrafast optical coherent acoustic phonon and optoelectronic properties of PdSe2 and may open new possibilities for PdSe2 applications in THz-frequency mechanical resonators.
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Affiliation(s)
- Chang-Fu Huo
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China.
| | - Rui Wen
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China.
| | - Xiao-Qing Yan
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China.
| | - De-Kang Li
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China.
| | - Kai-Xuan Huang
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China.
| | - Yizhi Zhu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Qiannan Cui
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Chunxiang Xu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Zhi-Bo Liu
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China. .,Renewable Energy Conversion and Storage Center, Nankai University, Tianjin 300071, China.,The collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jian-Guo Tian
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and Teda Applied Physics Institute, Nankai University, Tianjin 300071, China. .,Renewable Energy Conversion and Storage Center, Nankai University, Tianjin 300071, China.,The collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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7
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Pogna EA, Jia X, Principi A, Block A, Banszerus L, Zhang J, Liu X, Sohier T, Forti S, Soundarapandian K, Terrés B, Mehew JD, Trovatello C, Coletti C, Koppens FHL, Bonn M, Wang HI, van Hulst N, Verstraete MJ, Peng H, Liu Z, Stampfer C, Cerullo G, Tielrooij KJ. Hot-Carrier Cooling in High-Quality Graphene Is Intrinsically Limited by Optical Phonons. ACS NANO 2021; 15:11285-11295. [PMID: 34139125 PMCID: PMC8320233 DOI: 10.1021/acsnano.0c10864] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Many promising optoelectronic devices, such as broadband photodetectors, nonlinear frequency converters, and building blocks for data communication systems, exploit photoexcited charge carriers in graphene. For these systems, it is essential to understand the relaxation dynamics after photoexcitation. These dynamics contain a sub-100 fs thermalization phase, which occurs through carrier-carrier scattering and leads to a carrier distribution with an elevated temperature. This is followed by a picosecond cooling phase, where different phonon systems play a role: graphene acoustic and optical phonons, and substrate phonons. Here, we address the cooling pathway of two technologically relevant systems, both consisting of high-quality graphene with a mobility >10 000 cm2 V-1 s-1 and environments that do not efficiently take up electronic heat from graphene: WSe2-encapsulated graphene and suspended graphene. We study the cooling dynamics using ultrafast pump-probe spectroscopy at room temperature. Cooling via disorder-assisted acoustic phonon scattering and out-of-plane heat transfer to substrate phonons is relatively inefficient in these systems, suggesting a cooling time of tens of picoseconds. However, we observe much faster cooling, on a time scale of a few picoseconds. We attribute this to an intrinsic cooling mechanism, where carriers in the high-energy tail of the hot-carrier distribution emit optical phonons. This creates a permanent heat sink, as carriers efficiently rethermalize. We develop a macroscopic model that explains the observed dynamics, where cooling is eventually limited by optical-to-acoustic phonon coupling. These fundamental insights will guide the development of graphene-based optoelectronic devices.
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Affiliation(s)
- Eva A.
A. Pogna
- NEST,
Istituto Nanoscienze-CNR and Scuola Normale Superiore, 56127 Pisa, Italy
- Department
of Physics, Politecnico di Milano, 20133 Milan, Italy
| | - Xiaoyu Jia
- Max-Planck-Institut
für Polymerforschung, 55128 Mainz, Germany
| | - Alessandro Principi
- School
of Physics and Astronomy, University of
Manchester, M13 9PL Manchester, U.K.
| | - Alexander Block
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), BIST & CSIC, Campus UAB, Bellaterra, Barcelona 08193, Spain
| | - Luca Banszerus
- JARA-FIT
and second Institute of Physics, RWTH Aachen
University, 52074 Aachen, Germany, EU
| | - Jincan Zhang
- Center for
Nanochemistry, College of Chemistry and Molecular Engineering, Academy
for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Beijing
Graphene Institute, Beijing 100095, P. R. China
| | - Xiaoting Liu
- Center for
Nanochemistry, College of Chemistry and Molecular Engineering, Academy
for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Beijing
Graphene Institute, Beijing 100095, P. R. China
| | - Thibault Sohier
- NanoMat/Q-Mat/CESAM, Université
de Liège (B5), B-4000 Liège, Belgium
| | - Stiven Forti
- Center
for Nanotechnology Innovation IIT@NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | | | - Bernat Terrés
- ICFO - Institut de Ciències Fotòniques, BIST, Castelldefels, Barcelona 08860, Spain
| | - Jake D. Mehew
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), BIST & CSIC, Campus UAB, Bellaterra, Barcelona 08193, Spain
| | | | - Camilla Coletti
- Center
for Nanotechnology Innovation IIT@NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene Laboratories, Via Morego 30, 16163 Genova, Italy
| | - Frank H. L. Koppens
- ICFO - Institut de Ciències Fotòniques, BIST, Castelldefels, Barcelona 08860, Spain
- ICREA - Institució Catalana de Reçerca i Estudis Avancats, 08010 Barcelona, Spain
| | - Mischa Bonn
- Max-Planck-Institut
für Polymerforschung, 55128 Mainz, Germany
| | - Hai I. Wang
- Max-Planck-Institut
für Polymerforschung, 55128 Mainz, Germany
| | - Niek van Hulst
- ICFO - Institut de Ciències Fotòniques, BIST, Castelldefels, Barcelona 08860, Spain
- ICREA - Institució Catalana de Reçerca i Estudis Avancats, 08010 Barcelona, Spain
| | | | - Hailin Peng
- Center for
Nanochemistry, College of Chemistry and Molecular Engineering, Academy
for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Beijing
Graphene Institute, Beijing 100095, P. R. China
| | - Zhongfan Liu
- Center for
Nanochemistry, College of Chemistry and Molecular Engineering, Academy
for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Beijing
Graphene Institute, Beijing 100095, P. R. China
| | - Christoph Stampfer
- JARA-FIT
and second Institute of Physics, RWTH Aachen
University, 52074 Aachen, Germany, EU
| | - Giulio Cerullo
- Department
of Physics, Politecnico di Milano, 20133 Milan, Italy
| | - Klaas-Jan Tielrooij
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), BIST & CSIC, Campus UAB, Bellaterra, Barcelona 08193, Spain
- E-mail:
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8
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Massicotte M, Soavi G, Principi A, Tielrooij KJ. Hot carriers in graphene - fundamentals and applications. NANOSCALE 2021; 13:8376-8411. [PMID: 33913956 PMCID: PMC8118204 DOI: 10.1039/d0nr09166a] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/30/2021] [Indexed: 05/15/2023]
Abstract
Hot charge carriers in graphene exhibit fascinating physical phenomena, whose understanding has improved greatly over the past decade. They have distinctly different physical properties compared to, for example, hot carriers in conventional metals. This is predominantly the result of graphene's linear energy-momentum dispersion, its phonon properties, its all-interface character, and the tunability of its carrier density down to very small values, and from electron- to hole-doping. Since a few years, we have witnessed an increasing interest in technological applications enabled by hot carriers in graphene. Of particular interest are optical and optoelectronic applications, where hot carriers are used to detect (photodetection), convert (nonlinear photonics), or emit (luminescence) light. Graphene-enabled systems in these application areas could find widespread use and have a disruptive impact, for example in the field of data communication, high-frequency electronics, and industrial quality control. The aim of this review is to provide an overview of the most relevant physics and working principles that are relevant for applications exploiting hot carriers in graphene.
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Affiliation(s)
- Mathieu Massicotte
- Institut Quantique and Département de Physique, Université de SherbrookeSherbrookeQuébecCanada
| | - Giancarlo Soavi
- Institute of Solid State Physics, Friedrich Schiller University Jena07743 JenaGermany
- Abbe Center of Photonics, Friedrich Schiller University Jena07745 JenaGermany
| | | | - Klaas-Jan Tielrooij
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), BIST & CSIC, Campus UAB08193BellaterraBarcelonaSpain
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9
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Shin HJ, Kim J, Kim S, Choi H, Lee S, Lee YH, Son JH, Lim SC. Unsaturated Drift Velocity of Monolayer Graphene. NANO LETTERS 2018; 18:1575-1581. [PMID: 29415543 DOI: 10.1021/acs.nanolett.7b03566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We observe that carriers in graphene can be accelerated to the Fermi velocity without heating the lattice. At large Fermi energy | EF| > 110 meV, electrons excited by a high-power terahertz pulse ETHz relax by emitting optical phonons, resulting in heating of the graphene lattice and optical-phonon generation. This is owing to enhanced electron-phonon scattering at large Fermi energy, at which the large phase space is available for hot electrons. The emitted optical phonons cause carrier scattering, reducing the drift velocity or carrier mobility. However, for | EF| ≤ 110 meV, electron-phonon scattering rate is suppressed owing to the diminishing density of states near the Dirac point. Therefore, ETHz continues to accelerate carriers without them losing energy to optical phonons, allowing the carriers to travel at the Fermi velocity. The exotic carrier dynamics does not result from the massless nature, but the electron-optical-phonon scattering rate depends on Fermi level in the graphene. Our observations provide insight into the application of graphene for high-speed electronics without degrading carrier mobility.
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Affiliation(s)
- Hee Jun Shin
- Department of Physics , University of Seoul , Seoul 02504 , Republic of Korea
- Research Group of Food Safety , Korea Food Research Institute , Wanju 55365 , Republic of Korea
| | - Jaesu Kim
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Sungho Kim
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Homin Choi
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Sahnghyub Lee
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Young Hee Lee
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
- Department of Physics , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Joo-Hiuk Son
- Department of Physics , University of Seoul , Seoul 02504 , Republic of Korea
| | - Seong Chu Lim
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
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10
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Huang KC, McCall J, Wang P, Liao CS, Eakins G, Cheng JX, Yang C. High-Speed Spectroscopic Transient Absorption Imaging of Defects in Graphene. NANO LETTERS 2018; 18:1489-1497. [PMID: 29342361 DOI: 10.1021/acs.nanolett.7b05283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Graphene grain boundaries (GBs) and other nanodefects can deteriorate electronic properties. Here, using transient absorption (TA) microscopy we directly visualized GBs by TA intensity increase due to change in density of state. We also observed a faster decay due to defect-accelerated carrier relaxation in the GB area. By line-illumination and parallel detection, we increased the TA intensity imaging speed to 1000 frames per second, which is 6 orders of magnitude faster than Raman microscopy. Combined with a resonant optical delay tuner which scans a 5.3 ps temporal delay within 92 μs, our system enabled spectroscopic TA imaging, at a speed of 50 stacks per second, to probe and characterize graphene nanodefects based on the TA decay rate. Finally, we demonstrate real-time nondestructive characterization of graphene at a rolling speed of 0.3 m/min, which matches the fastest roll-to-roll manufacturing process reported.
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Affiliation(s)
- Kai-Chih Huang
- Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States
| | - Jeremy McCall
- Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States
| | - Pu Wang
- School of Biological Science and Medical Engineering, Beihang University , Beijing 100083, China
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University , Beijing 102402, China
| | - Chien-Sheng Liao
- Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States
| | - Gregory Eakins
- Jonathan Amy Facility for Chemical Instrumentation, Purdue University , West Lafayette, Indiana 47907, United States
| | - Ji-Xin Cheng
- Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States
- Department of Electrical and Computer Engineering, Boston University , Boston, Massachusetts 02215, United States
| | - Chen Yang
- Department of Electrical and Computer Engineering, Boston University , Boston, Massachusetts 02215, United States
- Department of Chemistry, Boston University , Boston, Massachusetts 02215, United States
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11
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Shin HJ, Kim J, Kim S, Kim H, Nguyen VL, Lee YH, Lim SC, Son JH. Transient Carrier Cooling Enhanced by Grain Boundaries in Graphene Monolayer. ACS APPLIED MATERIALS & INTERFACES 2017; 9:41026-41033. [PMID: 29072440 DOI: 10.1021/acsami.7b12812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Using a high terahertz (THz) electric field (ETHz), the carrier scattering in graphene was studied with an electric field of up to 282 kV/cm. When the grain size of graphene monolayers varies from small (5 μm) and medium (70 μm) to large grains (500 μm), the dominant carrier scattering source in large- and small-grained graphene differs at high THz field, i.e., there is optical phonon scattering for large grains and defect scattering for small grains. Although the electron-optical phonon coupling strength is the same for all grain sizes in our study, the enhanced optical phonon scattering in the high THz field from the large-grained graphene is caused by a higher optical phonon temperature, originating from the slow relaxation of accelerated electrons. Unlike the large-grained graphene, lower electron and optical phonon temperatures are found in the small-grained graphene monolayer, resulting from the effective carrier cooling through the defects, called supercollisions. Our results indicate that the carrier mobility in the high-crystalline graphene is easily vulnerable to scattering by the optical phonons. Thus, controlling the population of defect sites, as a means for carrier cooling, can enhance the carrier mobility at high electric fields in graphene electronics by suppressing the heating of optical phonons.
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Affiliation(s)
- Hee Jun Shin
- Department of Physics, University of Seoul , Seoul 02504, Republic of Korea
- Research Group of Food Safety, Korea Food Research Institute , Wanju 55365, Republic of Korea
| | | | | | - Hyeongmun Kim
- Department of Physics, University of Seoul , Seoul 02504, Republic of Korea
| | | | | | | | - Joo-Hiuk Son
- Department of Physics, University of Seoul , Seoul 02504, Republic of Korea
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12
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Wendler F, Mittendorff M, König-Otto JC, Brem S, Berger C, de Heer WA, Böttger R, Schneider H, Helm M, Winnerl S, Malic E. Symmetry-Breaking Supercollisions in Landau-Quantized Graphene. PHYSICAL REVIEW LETTERS 2017; 119:067405. [PMID: 28949645 DOI: 10.1103/physrevlett.119.067405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 06/07/2023]
Abstract
Recent pump-probe experiments performed on graphene in a perpendicular magnetic field have revealed carrier relaxation times ranging from picoseconds to nanoseconds depending on the quality of the sample. To explain this surprising behavior, we propose a novel symmetry-breaking defect-assisted relaxation channel. This enables scattering of electrons with single out-of-plane phonons, which drastically accelerate the carrier scattering time in low-quality samples. The gained insights provide a strategy for tuning the carrier relaxation time in graphene and related materials by orders of magnitude.
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Affiliation(s)
- Florian Wendler
- Department of Theoretical Physics, Technical University Berlin, 10623 Berlin, Germany
| | - Martin Mittendorff
- Institute for Research in Electronics & Applied Physics, University of Maryland, College Park, Maryland 20742, USA
- Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany
| | - Jacob C König-Otto
- Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany
- Technische Universität Dresden, D-01062 Dresden, Germany
| | - Samuel Brem
- Department of Theoretical Physics, Technical University Berlin, 10623 Berlin, Germany
| | - Claire Berger
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- Institut Néel, CNRS-Université Alpes, 38042 Grenoble, France
| | | | - Roman Böttger
- Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany
| | - Harald Schneider
- Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany
| | - Manfred Helm
- Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany
- Technische Universität Dresden, D-01062 Dresden, Germany
| | - Stephan Winnerl
- Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany
| | - Ermin Malic
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
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13
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Alencar TV, Malard LM, Paula AMD. Supercollision cooling effects on the hot photoluminescence emission of graphene. NANOTECHNOLOGY 2016; 27:445710. [PMID: 27688264 DOI: 10.1088/0957-4484/27/44/445710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on hot photoluminescence measurements that show the effects of acoustic phonon supercollision processes in the intensity of graphene light emission. We use a simple optical method to induce defects on single layer graphene in a controlled manner to study in detail the light emission dependence on the sample defect density. It is now well accepted that the graphene photoluminescence is due to black-body thermal emission from the quasi-equilibrium electrons at a temperature well above the lattice temperature. Our results show that as the sample defect density is increased the electrons relax energy more efficiently via acoustic phonon supercollision processes leading to lower electron temperatures and thus lower emission intensities. The calculated intensity decrease due to supercollision energy relaxation agrees well with the experimental data.
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Affiliation(s)
- Thonimar V Alencar
- Departamento de Física, Universidade Federal de Minas Gerais, Caixa Postal 702, 30123-970 Belo Horizonte-MG, Brazil
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14
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Tielrooij KJ, Massicotte M, Piatkowski L, Woessner A, Ma Q, Jarillo-Herrero P, van Hulst NF, Koppens FHL. Hot-carrier photocurrent effects at graphene-metal interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:164207. [PMID: 25835338 DOI: 10.1088/0953-8984/27/16/164207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Photoexcitation of graphene leads to an interesting sequence of phenomena, some of which can be exploited in optoelectronic devices based on graphene. In particular, the efficient and ultrafast generation of an electron distribution with an elevated electron temperature and the concomitant generation of a photo-thermoelectric voltage at symmetry-breaking interfaces is of interest for photosensing and light harvesting. Here, we experimentally study the generated photocurrent at the graphene-metal interface, focusing on the time-resolved photocurrent, the effects of photon energy, Fermi energy and light polarization. We show that a single framework based on photo-thermoelectric photocurrent generation explains all experimental results.
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Affiliation(s)
- K J Tielrooij
- ICFO-Institut de Ciéncies Fotóniques, Mediterranean Technology Park, Castelldefels (Barcelona) 08860, Spain
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