1
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Bakalis J, Chernov S, Li Z, Kunin A, Withers ZH, Cheng S, Adler A, Zhao P, Corder C, White MG, Schönhense G, Du X, Kawakami RK, Allison TK. Momentum-Space Observation of Optically Excited Nonthermal Electrons in Graphene with Persistent Pseudospin Polarization. NANO LETTERS 2024. [PMID: 39037901 DOI: 10.1021/acs.nanolett.4c02378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
The unique optical properties of graphene, with broadband absorption and ultrafast response, make it a critical component of optoelectronic and spintronic devices. Using time-resolved momentum microscopy with high data rate and high dynamic range, we report momentum-space measurements of electrons promoted to the graphene conduction band with visible light and their subsequent relaxation. We observe a pronounced nonthermal distribution of nascent photoexcited electrons with lattice pseudospin polarization in remarkable agreement with results of simple tight-binding theory. By varying the excitation fluence, we vary the relative importance of electron-electron vs electron-phonon scattering in the relaxation of the initial distribution. Increasing the excitation fluence results in increased noncollinear electron-electron scattering and reduced pseudospin polarization, although up-scattered electrons retain a degree of polarization. These detailed momentum-resolved electron dynamics in graphene demonstrate the capabilities of high-performance time-resolved momentum microscopy in the study of 2D materials and can inform the design of graphene devices.
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Affiliation(s)
- Jin Bakalis
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Sergii Chernov
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Ziling Li
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Alice Kunin
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Zachary H Withers
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, United States
| | - Shuyu Cheng
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Alexander Adler
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, United States
| | - Peng Zhao
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Christopher Corder
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Michael G White
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973 United States
| | - Gerd Schönhense
- Johannes Gutenberg-Universität, Institut für Physik, D-55099 Mainz, Germany
| | - Xu Du
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, United States
| | - Roland K Kawakami
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Thomas K Allison
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, United States
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2
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Fedorov AS, Eremkin EV, Krasnov PO, Gerasimov VS, Ågren H, Polyutov SP. A hybrid quantum-classical theory for predicting terahertz charge-transfer plasmons in metal nanoparticles on graphene. J Chem Phys 2024; 160:044117. [PMID: 38294310 DOI: 10.1063/5.0178247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/07/2024] [Indexed: 02/01/2024] Open
Abstract
Metal nanoparticle (NP) complexes lying on a single-layer graphene surface are studied with a developed original hybrid quantum-classical theory using the Finite Element Method (FEM) that is computationally cheap. Our theory is based on the motivated assumption that the carrier charge density in the doped graphene does not vary significantly during the plasmon oscillations. Charge transfer plasmon (CTP) frequencies, eigenvectors, quality factors, energy loss in the NPs and in graphene, and the absorption power are aspects that are theoretically studied and numerically calculated. It is shown the CTP frequencies reside in the terahertz range and can be represented as a product of two factors: the Fermi level of graphene and the geometry of the NP complex. The energy losses in the NPs are predicted to be inversely dependent on the radius R of the nanoparticle, while the loss in graphene is proportional to R and the interparticle distance. The CTP quality factors are predicted to be in the range ∼10-100. The absorption power under CTP excitation is proportional to the scalar product of the CTP dipole moment and the external electromagnetic field. The developed theory makes it possible to simulate different properties of CTPs 3-4 orders of magnitude faster compared to the original FEM or the finite-difference time domain method, providing possibilities for predicting the plasmonic properties of very large systems for different applications.
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Affiliation(s)
- A S Fedorov
- International Research Center of Spectroscopy and Quantum Chemistry, Siberian Federal University, 660041 Krasnoyarsk, Russia
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk, Russia
| | - E V Eremkin
- International Research Center of Spectroscopy and Quantum Chemistry, Siberian Federal University, 660041 Krasnoyarsk, Russia
| | - P O Krasnov
- International Research Center of Spectroscopy and Quantum Chemistry, Siberian Federal University, 660041 Krasnoyarsk, Russia
| | - V S Gerasimov
- Institute of Computational Modeling SB RAS, 660036 Krasnoyarsk, Russia
| | - H Ågren
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - S P Polyutov
- International Research Center of Spectroscopy and Quantum Chemistry, Siberian Federal University, 660041 Krasnoyarsk, Russia
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3
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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: 29] [Impact Index Per Article: 9.7] [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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4
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Yang LX, Rohde G, Hanff K, Stange A, Xiong R, Shi J, Bauer M, Rossnagel K. Bypassing the Structural Bottleneck in the Ultrafast Melting of Electronic Order. PHYSICAL REVIEW LETTERS 2020; 125:266402. [PMID: 33449703 DOI: 10.1103/physrevlett.125.266402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
Impulsive optical excitation generally results in a complex nonequilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs the gap in the electronic spectrum is not seriously affected by lattice vibrations. Here, however, by directly monitoring the photoinduced collapse of the spectral gap in a canonical charge-density-wave material, the blue bronze Rb_{0.3}MoO_{3}, we find that ultrafast (∼60 fs) vibrational disordering due to efficient hot-electron energy dissipation quenches the gap significantly faster than the typical structural bottleneck time corresponding to one half-cycle oscillation (∼315 fs) of the coherent charge-density-wave amplitude mode. This result not only demonstrates the importance of incoherent lattice motion in the photoinduced quenching of electronic order, but also resolves the perennial debate about the nature of the spectral gap in a coupled electron-lattice system.
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Affiliation(s)
- L X Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
- Frontier Science Center for Quantum Information, Beijing 100084, People's Republic of China
| | - G Rohde
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - K Hanff
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - A Stange
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - R Xiong
- Department of Physics, Wuhan University, Wuhan 430072, People's Republic of China
| | - J Shi
- Department of Physics, Wuhan University, Wuhan 430072, People's Republic of China
| | - M Bauer
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - K Rossnagel
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
- Ruprecht-Haensel-Labor, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
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5
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Huang P, Riccardi E, Messelot S, Graef H, Valmorra F, Tignon J, Taniguchi T, Watanabe K, Dhillon S, Plaçais B, Ferreira R, Mangeney J. Ultra-long carrier lifetime in neutral graphene-hBN van der Waals heterostructures under mid-infrared illumination. Nat Commun 2020; 11:863. [PMID: 32054848 PMCID: PMC7018796 DOI: 10.1038/s41467-020-14714-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/27/2020] [Indexed: 12/03/2022] Open
Abstract
Graphene/hBN heterostructures are promising active materials for devices in the THz domain, such as emitters and photodetectors based on interband transitions. Their performance requires long carrier lifetimes. However, carrier recombination processes in graphene possess sub-picosecond characteristic times for large non-equilibrium carrier densities at high energy. An additional channel has been recently demonstrated in graphene/hBN heterostructures by emission of hBN hyperbolic phonon polaritons (HPhP) with picosecond decay time. Here, we report on carrier lifetimes in graphene/hBN Zener-Klein transistors of ~30 ps for photoexcited carriers at low density and energy, using mid-infrared photoconductivity measurements. We further demonstrate the switching of carrier lifetime from ~30 ps (attributed to interband Auger) down to a few picoseconds upon ignition of HPhP relaxation at finite bias and/or with infrared excitation power. Our study opens interesting perspectives to exploit graphene/hBN heterostructures for THz lasing and highly sensitive THz photodetection as well as for phonon polariton optics. Long carrier lifetimes are beneficial for graphene-based optoelectronics, but carrier recombination processes in graphene possess sub-picosecond characteristic times. Here, the authors report carrier lifetimes ~30 ps at low energy in graphene/hBN Zener-Klein transistors, attributed to interband Auger processes.
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Affiliation(s)
- P Huang
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France.,State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - E Riccardi
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - S Messelot
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - H Graef
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - F Valmorra
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - J Tignon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - T Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047, Japan
| | - K Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047, Japan
| | - S Dhillon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - B Plaçais
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - R Ferreira
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France
| | - J Mangeney
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne, Université, Université de Paris, 75005, Paris, France.
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6
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Ultrafast Hyperspectral Transient Absorption Spectroscopy: Application to Single Layer Graphene. PHOTONICS 2019. [DOI: 10.3390/photonics6030095] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We describe the basic principles and the experimental implementation of the hyperspectral transient absorption technique, based on femtosecond laser sources. In this technique the samples were optically “pumped” using the femtosecond tunable pulse delivered by an Optical Parametric Amplifier, and “probed” for changes in transmission in a broad spectral range with a “white light” laser-generated supercontinuum. The spectra were collected by a pair of multichannel detectors which allowed retrieval of the absorbance change in a wide spectral range in one time. The use of the supercontinuum probe introduced artifacts in the measured 2D data set which could be corrected with a proper calibration of the chirp. The configuration with crossed polarization for pump and probe pulse extended the spectral measured range above and below the pump energy within the same experiment. We showed the versatility of the technique by applying it to the investigation of the charge carrier dynamics in two-dimensional single layer graphene.
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7
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Ma Q, Lui CH, Song JCW, Lin Y, Kong JF, Cao Y, Dinh TH, Nair NL, Fang W, Watanabe K, Taniguchi T, Xu SY, Kong J, Palacios T, Gedik N, Gabor NM, Jarillo-Herrero P. Giant intrinsic photoresponse in pristine graphene. NATURE NANOTECHNOLOGY 2019; 14:145-150. [PMID: 30559484 DOI: 10.1038/s41565-018-0323-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
When the Fermi level is aligned with the Dirac point of graphene, reduced charge screening greatly enhances electron-electron scattering1-5. In an optically excited system, the kinematics of electron-electron scattering in Dirac fermions is predicted to give rise to novel optoelectronic phenomena6-11. In this paper, we report on the observation of an intrinsic photocurrent in graphene, which occurs in a different parameter regime from all the previously observed photothermoelectric or photovoltaic photocurrents in graphene12-20: the photocurrent emerges exclusively at the charge neutrality point, requiring no finite doping. Unlike other photocurrent types that are enhanced near p-n or contact junctions, the photocurrent observed in our work arises near the edges/corners. By systematic data analyses, we show that the phenomenon stems from the unique electron-electron scattering kinematics in charge-neutral graphene. Our results not only highlight the intriguing electron dynamics in the optoelectronic response of Dirac fermions, but also offer a new scheme for photodetection and energy harvesting applications based on intrinsic, charge-neutral Dirac fermions.
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Affiliation(s)
- Qiong Ma
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Chun Hung Lui
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | - Justin C W Song
- Division of Physics & Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
- Institute of High Performance Computing, Agency for Science, Technology, & Research, Singapore, Singapore
| | - Yuxuan Lin
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jian Feng Kong
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yuan Cao
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Thao H Dinh
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nityan L Nair
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, University of California, Berkeley, CA, USA
| | - Wenjing Fang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | | | - Su-Yang Xu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jing Kong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tomás Palacios
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nuh Gedik
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nathaniel M Gabor
- Department of Physics and Astronomy, University of California, Riverside, CA, USA.
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8
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Rohde G, Stange A, Müller A, Behrendt M, Oloff LP, Hanff K, Albert TJ, Hein P, Rossnagel K, Bauer M. Ultrafast Formation of a Fermi-Dirac Distributed Electron Gas. PHYSICAL REVIEW LETTERS 2018; 121:256401. [PMID: 30608821 DOI: 10.1103/physrevlett.121.256401] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 09/22/2018] [Indexed: 06/09/2023]
Abstract
Time- and angle-resolved photoelectron spectroscopy with 13 fs temporal resolution is used to follow the different stages in the formation of a Fermi-Dirac distributed electron gas in graphite after absorption of an intense 7 fs laser pulse. Within the first 50 fs after excitation, a sequence of time frames is resolved that are characterized by different energy and momentum exchange processes among the involved photonic, electronic, and phononic degrees of freedom. The results reveal experimentally the complexity of the transition from a nascent nonthermal towards a thermal electron distribution due to the different timescales associated with the involved interaction processes.
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Affiliation(s)
- G Rohde
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - A Stange
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - A Müller
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - M Behrendt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - L-P Oloff
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - K Hanff
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - T J Albert
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - P Hein
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - K Rossnagel
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - M Bauer
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
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9
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Tomadin A, Hornett SM, Wang HI, Alexeev EM, Candini A, Coletti C, Turchinovich D, Kläui M, Bonn M, Koppens FHL, Hendry E, Polini M, Tielrooij KJ. The ultrafast dynamics and conductivity of photoexcited graphene at different Fermi energies. SCIENCE ADVANCES 2018; 4:eaar5313. [PMID: 29756035 PMCID: PMC5947979 DOI: 10.1126/sciadv.aar5313] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 03/23/2018] [Indexed: 05/06/2023]
Abstract
For many of the envisioned optoelectronic applications of graphene, it is crucial to understand the subpicosecond carrier dynamics immediately following photoexcitation and the effect of photoexcitation on the electrical conductivity-the photoconductivity. Whereas these topics have been studied using various ultrafast experiments and theoretical approaches, controversial and incomplete explanations concerning the sign of the photoconductivity, the occurrence and significance of the creation of additional electron-hole pairs, and, in particular, how the relevant processes depend on Fermi energy have been put forward. We present a unified and intuitive physical picture of the ultrafast carrier dynamics and the photoconductivity, combining optical pump-terahertz probe measurements on a gate-tunable graphene device, with numerical calculations using the Boltzmann equation. We distinguish two types of ultrafast photo-induced carrier heating processes: At low (equilibrium) Fermi energy (EF ≲ 0.1 eV for our experiments), broadening of the carrier distribution involves interband transitions (interband heating). At higher Fermi energy (EF ≳ 0.15 eV), broadening of the carrier distribution involves intraband transitions (intraband heating). Under certain conditions, additional electron-hole pairs can be created [carrier multiplication (CM)] for low EF, and hot carriers (hot-CM) for higher EF. The resultant photoconductivity is positive (negative) for low (high) EF, which in our physical picture, is explained using solely electronic effects: It follows from the effect of the heated carrier distributions on the screening of impurities, consistent with the DC conductivity being mostly due to impurity scattering. The importance of these insights is highlighted by a discussion of the implications for graphene photodetector applications.
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Affiliation(s)
- Andrea Tomadin
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163 Genova, Italy
- Corresponding author. (K.-J.T.); (A.T.)
| | - Sam M. Hornett
- School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Hai I. Wang
- Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | | | - Andrea Candini
- Centro S3, Istituto Nanoscienze-CNR, via Campi 213/a 41125 Modena, Italy
| | - Camilla Coletti
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163 Genova, Italy
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Dmitry Turchinovich
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
- Fakultät für Physik, Universität Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Mathias Kläui
- Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Frank H. L. Koppens
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- ICREA - Institució Catalana de Reçerca i Estudis Avancats, 08010 Barcelona, Spain
| | - Euan Hendry
- School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Marco Polini
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163 Genova, Italy
| | - Klaas-Jan Tielrooij
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- Corresponding author. (K.-J.T.); (A.T.)
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10
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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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Winzer T, Mittendorff M, Winnerl S, Mittenzwey H, Jago R, Helm M, Malic E, Knorr A. Unconventional double-bended saturation of carrier occupation in optically excited graphene due to many-particle interactions. Nat Commun 2017; 8:15042. [PMID: 28485387 PMCID: PMC5436067 DOI: 10.1038/ncomms15042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 02/24/2017] [Indexed: 11/08/2022] Open
Abstract
Saturation of carrier occupation in optically excited materials is a well-established phenomenon. However, so far, the observed saturation effects have always occurred in the strong-excitation regime and have been explained by Pauli blocking of the optically filled quantum states. On the basis of microscopic theory combined with ultrafast pump-probe experiments, we reveal a new low-intensity saturation regime in graphene that is purely based on many-particle scattering and not Pauli blocking. This results in an unconventional double-bended saturation behaviour: both bendings separately follow the standard saturation model exhibiting two saturation fluences; however, the corresponding fluences differ by three orders of magnitude and have different physical origin. Our results demonstrate that this new and unexpected behaviour can be ascribed to an interplay between time-dependent many-particle scattering and phase-space filling effects.
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Affiliation(s)
- Torben Winzer
- Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Martin Mittendorff
- Institute for Research in Electronics & Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - Stephan Winnerl
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
| | - Henry Mittenzwey
- Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Roland Jago
- Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Manfred Helm
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
- Institut für Angewandte Physik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Ermin Malic
- Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Andreas Knorr
- Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
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