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Yu Q, Feng S, Yu J, Cheng S, Lai Y, Chen Y, He K. Manipulation of Helicity-Dependent Photocurrent and Stokes Parameter Detection in Topological Insulator Bi 2Te 3 Nanowires. ACS APPLIED MATERIALS & INTERFACES 2024; 16:40297-40308. [PMID: 39016434 DOI: 10.1021/acsami.4c11221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Helicity-dependent photocurrent (HDPC) and its modulation in topological insulator Bi2Te3 nanowires have been investigated. It is revealed that when the incident plane of a laser is perpendicular to the nanowire, the HDPC is an odd function of the incident angle, which is mainly contributed by the circular photogalvanic effect originating from the surface states of Bi2Te3 nanowire. When the incident plane of a laser is parallel to the nanowire, the HDPC is approximately an even function of the incident angle, which is due to the circular photon drag effect coming from the surface states. It is found that the HDPC can be effectively tuned by the back gate and the ionic liquid top gate. By analyzing the substrate dependence of the HDPC, we find that the HDPC of the Bi2Te3 nanowire on the Si substrate is an order of magnitude larger than that on SiO2, which may be due to the spin injection from the Si substrate to the Bi2Te3 nanowire. In addition, by applying different biases, the Stokes parameters of a polarized light can be extracted by arithmetic operation of the photocurrents measured in the Bi2Te3 nanowire. This work suggests that topological insulator Bi2Te3 nanowires may provide a good platform for opto-spintronic devices, especially in chirality and polarimtry detection.
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Affiliation(s)
- Qin Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Shizun Feng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Jinling Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
- Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Shuying Cheng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Yunfeng Lai
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Yonghai Chen
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ke He
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
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2
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Zou X, Yuan X, Liang L, Tian F, Li Y, Sun Y, Wang C. Unusual Janus Bi 2TeSe 2 Topological Insulators Displaying Second-Harmonic Generation, Linear-in-Temperature Resistivity, and Weak Antilocalization. J Am Chem Soc 2024; 146:17784-17792. [PMID: 38916273 DOI: 10.1021/jacs.4c03176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Well-established knowledge about inversion-symmetric Bi2TexSe3-x topological insulators characterizes the promising new-generation quantum device. Noticeably, the inversion asymmetric phase containing different surface electronic structures may create an extra topological phenomenon pointing to a new device paradigm. Herein, Janus Bi2TeSe2 single-crystal nanosheets with an unconventional stacking sequence of Se-Bi-Se-Bi-Te are realized via chemical vapor deposition growth, which is clarified by atomically resolved AC-STEM and elemental mapping. An obvious polarization-dependent second-harmonic generation with a representative 6-fold rotational symmetry is detected due to the broken out-of-plane mirror symmetry in this system. Low-temperature transport measurements display a strange metal-like linear-in-temperature resistivity. Anomalous conductance peaks under low magnetic fields induced by the weak antilocalization effect of topological surface states and the two-dimensional transport-dominated anisotropic magnetoresistance are revealed. These findings correlate the Janus Bi2TeSe2 phase with emerging physics topics, which would inspire fresh thoughts in well-developed Bi3TexSe3-x topological insulators and open up opportunities for exploring hybrid nonlinear optoelectronic topological devices.
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Affiliation(s)
- Xiaobin Zou
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Xuanhao Yuan
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Lishan Liang
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Fei Tian
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Yan Li
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Yong Sun
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Chengxin Wang
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
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3
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Fukumoto K, Lee S, Adachi SI, Suzuki Y, Kusakabe K, Yamamoto R, Kitatani M, Ishida K, Nakagawa Y, Merkel M, Shiga D, Kumigashira H. Surface terminations control charge transfer from bulk to surface states in topological insulators. Sci Rep 2024; 14:10537. [PMID: 38719934 PMCID: PMC11079079 DOI: 10.1038/s41598-024-61172-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 05/02/2024] [Indexed: 05/12/2024] Open
Abstract
Topological insulators (TI) hold significant potential for various electronic and optoelectronic devices that rely on the Dirac surface state (DSS), including spintronic and thermoelectric devices, as well as terahertz detectors. The behavior of electrons within the DSS plays a pivotal role in the performance of such devices. It is expected that DSS appear on a surface of three dimensional(3D) TI by mechanical exfoliation. However, it is not always the case that the surface terminating atomic configuration and corresponding band structures are homogeneous. In order to investigate the impact of surface terminating atomic configurations on electron dynamics, we meticulously examined the electron dynamics at the exfoliated surface of a crystalline 3D TI (Bi2 Se3 ) with time, space, and energy resolutions. Based on our comprehensive band structure calculations, we found that on one of the Se-terminated surfaces, DSS is located within the bulk band gap, with no other surface states manifesting within this region. On this particular surface, photoexcited electrons within the conduction band effectively relax towards DSS and tend to linger at the Dirac point for extended periods of time. It is worth emphasizing that these distinct characteristics of DSS are exclusively observed on this particular surface.
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Affiliation(s)
- Keiki Fukumoto
- High energy accelerator research organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan.
| | - Seunghee Lee
- High energy accelerator research organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
| | - Shin-Ichi Adachi
- High energy accelerator research organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
| | - Yuta Suzuki
- The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, 240-0193, Japan
| | - Koichi Kusakabe
- University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Rikuto Yamamoto
- University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Motoharu Kitatani
- University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Kunio Ishida
- Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi, 321-8585, Japan
| | | | - Michael Merkel
- FOCUS GmbH, Neukirchner Str.2, 65510, Huenstetten, Germany
| | - Daisuke Shiga
- Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
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Huang S, Ghosh N, Niu C, Chen YP, Ye PD, Xu X. Optically Gated Electrostatic Field-Effect Thermal Transistor. NANO LETTERS 2024; 24:5139-5145. [PMID: 38639471 DOI: 10.1021/acs.nanolett.3c05085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Dynamic tuning of thermal transport in solids is scientifically intriguing with wide applications for thermal transport control in electronic devices. In this work, we demonstrate a thermal transistor, a device in which heat flow can be regulated using external control, realized in a topological insulator (TI) through the topological surface states. The tuning of thermal transport is achieved by using optical gating of a thin dielectric layer deposited on the TI film. The gate-dependent thermal conductivity is measured using micro-Raman thermometry. The transistor has a large ON/OFF ratio of 2.8 at room temperature and can be continuously and repetitively switched in tens of seconds by optical gating and potentially much faster by electrical gating. Such thermal transistors with a large ON/OFF ratio and fast switching times offer the possibilities of smart thermal devices for active thermal management and control in future electronic systems.
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Affiliation(s)
- Shouyuan Huang
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Neil Ghosh
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Chang Niu
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yong P Chen
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
| | - Peide D Ye
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
| | - Xianfan Xu
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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Li M, Wang Z, Han D, Shi X, Li T, Gao XP, Zhang Z. High photodetection performance on vertically oriented topological insulator Sb2Te3/Silicon heterostructure. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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6
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Luo MB, Cao QW, Huang SL, Lai HD, Zhou X, Lin Q. Modification of metallic and non-metallic sites in pentasupertetrahedral chalcogenidometalate clusters for third-order nonlinear optical response. Dalton Trans 2022; 51:2660-2663. [PMID: 35112694 DOI: 10.1039/d1dt04267j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four isomorphic P2 chalcogenide clusters named [Sn11In9Cu6S44]·11(H+DBU) (1) (DBU = 1,8-diazabicyclo[5.4.0] undec-7-ene), [Sn10In10Cu6Se44]·6(H22+DMAPA)·2(DMAPA)·9EG (2) (DMAPA = 3-dimethylaminopropylamine, EG = ethylene glycol), [Sn10In10Cu6S40O4]·6[H22+PMDETA]·10EG (3) (PMDETA = pentamethyldiethylenetriamine), [Sn10Ga10Cu6S40O4]·6(H22+DMAPA)·7EG (4) have been isolated via organotin precursor and mixed-metal strategy. These clusters exhibit excellent solubility in organic solvents. The continuous-regulation of optical band and optical limiting performance have been realized through precise controlled substituting engineering of cationic and anionic elements.
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Affiliation(s)
- Ming-Bu Luo
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
| | - Qian-Wen Cao
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
| | - Shan-Lin Huang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
| | - Heng-Dong Lai
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
| | - Xuechou Zhou
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qipu Lin
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
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7
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Xi F, Yang H, Khayrudinov V, He Y, Haggren T, Zhou Y, Lipsanen H, Sun Z, Xu X. Enhanced terahertz emission from mushroom-shaped InAs nanowire network induced by linear and nonlinear optical effects. NANOTECHNOLOGY 2021; 33:085207. [PMID: 34768252 DOI: 10.1088/1361-6528/ac3948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
The development of powerful terahertz (THz) emitters is the cornerstone for future THz applications, such as communication, medical biology, non-destructive inspection, and scientific research. Here, we report the THz emission properties and mechanisms of mushroom-shaped InAs nanowire (NW) network using linearly polarized laser excitation. By investigating the dependence of THz signal to the incidence pump light properties (e.g. incident angle, direction, fluence, and polarization angle), we conclude that the THz wave emission from the InAs NW network is induced by the combination of linear and nonlinear optical effects. The former is a transient photocurrent accelerated by the photo-Dember field, while the latter is related to the resonant optical rectification effect. Moreover, thep-polarized THz wave emission component is governed by the linear optical effect with a proportion of ∼85% and the nonlinear optical effect of ∼15%. In comparison, thes-polarized THz wave emission component is mainly decided by the nonlinear optical effect. The THz emission is speculated to be enhanced by the localized surface plasmon resonance absorption of the In droplets on top of the NWs. This work verifies the nonlinear optical mechanism in the THz generation of semiconductor NWs and provides an enlightening reference for the structural design of powerful and flexible THz surface and interface emitters in transmission geometry.
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Affiliation(s)
- Fugang Xi
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, School of Physics, Northwest University, Xi'an 710127, People's Republic of China
| | - He Yang
- School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing 100191, People's Republic of China
- Department of Electronics and Nanoengineering, Aalto University, Espoo, PO Box 13500, FI-00076, Finland
| | - Vladislav Khayrudinov
- Department of Electronics and Nanoengineering, Aalto University, Espoo, PO Box 13500, FI-00076, Finland
| | - Yuhang He
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, School of Physics, Northwest University, Xi'an 710127, People's Republic of China
| | - Tuomas Haggren
- Department of Electronics and Nanoengineering, Aalto University, Espoo, PO Box 13500, FI-00076, Finland
| | - Yixuan Zhou
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, School of Physics, Northwest University, Xi'an 710127, People's Republic of China
| | - Harri Lipsanen
- Department of Electronics and Nanoengineering, Aalto University, Espoo, PO Box 13500, FI-00076, Finland
| | - Zhipei Sun
- Department of Electronics and Nanoengineering, Aalto University, Espoo, PO Box 13500, FI-00076, Finland
| | - Xinlong Xu
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, School of Physics, Northwest University, Xi'an 710127, People's Republic of China
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8
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Mithun KP, Kar S, Kumar A, Muthu DVS, Ravishankar N, Sood AK. Dirac surface plasmons in photoexcited bismuth telluride nanowires: optical pump-terahertz probe spectroscopy. NANOSCALE 2021; 13:8283-8292. [PMID: 33890585 DOI: 10.1039/d0nr09087e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Collective excitation of Dirac plasmons in graphene and topological insulators has opened new possibilities of tunable plasmonic materials ranging from THz to mid-infrared regions. Using time resolved Optical Pump-Terahertz Probe (OPTP) spectroscopy, we demonstrate the presence of plasmonic oscillations in bismuth telluride nanowires (Bi2Te3 NWs) after photoexcitation using an 800 nm pump pulse. In the frequency domain, the differential conductivity (Δσ = σpump on-σpump off) spectrum shows a Lorentzian response where the resonance frequency (ωp), attributed to surface plasmon oscillations, shifts with photogenerated carrier density (n) as . This dependence establishes the absorption of THz radiation by the Dirac surface plasmon oscillations of the charge carriers in the Topological Surface States (TSS) of Bi2Te3 NWs. Moreover, we obtain a modulation depth, tunable by pump fluence, of ∼40% over the spectral range of 0.5 to 2.5 THz. In addition, the time evolution of Δσ(t) represents a long relaxation channel lasting for more than 50 ps. We model the decay dynamics of Δσ(t) using coupled second order rate equations, highlighting the contributions from surface recombination as well as from trap mediated relaxation channels of the photoinjected carriers.
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Affiliation(s)
- K P Mithun
- Center for Ultrafast Laser Applications, Indian Institute of Science, Bangalore 560012, India.
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9
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Sun X, Adamo G, Eginligil M, Krishnamoorthy HNS, Zheludev NI, Soci C. Topological insulator metamaterial with giant circular photogalvanic effect. SCIENCE ADVANCES 2021; 7:eabe5748. [PMID: 33811072 PMCID: PMC11057521 DOI: 10.1126/sciadv.abe5748] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
One of the most notable manifestations of electronic properties of topological insulators is the dependence of the photocurrent direction on the helicity of circularly polarized optical excitation. The helicity-dependent photocurrents, underpinned by spin-momentum locking of surface Dirac electrons, are weak and easily overshadowed by bulk contributions. Here, we show that the chiral response can be enhanced by nanostructuring. The tight confinement of electromagnetic fields in the resonant nanostructure enhances the photoexcitation of spin-polarized surface states of topological insulator Bi1.5Sb0.5Te1.8Se1.2, leading to an 11-fold increase of the circular photogalvanic effect and a previously unobserved photocurrent dichroism (ρcirc = 0.87) at room temperature. The control of spin transport in topological materials by structural design is a previously unrecognized ability of metamaterials that bridges the gap between nanophotonics and spin electronics, providing opportunities for developing polarization-sensitive photodetectors.
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Affiliation(s)
- X Sun
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - G Adamo
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - M Eginligil
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - H N S Krishnamoorthy
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - N I Zheludev
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK
| | - C Soci
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore.
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
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10
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Xie F, Lian Z, Zhang S, Wang T, Miao S, Song Z, Ying Z, Pan XC, Long M, Zhang M, Fei F, Hu W, Yu G, Song F, Kang TT, Shi SF. Reversible engineering of topological insulator surface state conductivity through optical excitation. NANOTECHNOLOGY 2021; 32:17LT01. [PMID: 33620033 DOI: 10.1088/1361-6528/abde01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Despite the broadband response, limited optical absorption at a particular wavelength hinders the development of optoelectronics based on Dirac fermions. Heterostructures of graphene and various semiconductors have been explored for this purpose, while non-ideal interfaces often limit the performance. The topological insulator (TI) is a natural hybrid system, with the surface states hosting high-mobility Dirac fermions and the small-bandgap semiconducting bulk state strongly absorbing light. In this work, we show a large photocurrent response from a field effect transistor device based on intrinsic TI Sn-Bi1.1Sb0.9Te2S (Sn-BSTS). The photocurrent response is non-volatile and sensitively depends on the initial Fermi energy of the surface state, and it can be erased by controlling the gate voltage. Our observations can be explained with a remote photo-doping mechanism, in which the light excites the defects in the bulk and frees the localized carriers to the surface state. This photodoping modulates the surface state conductivity without compromising the mobility, and it also significantly modify the quantum Hall effect of the surface state. Our work thus illustrates a route to reversibly manipulate the surface states through optical excitation, shedding light into utilizing topological surface states for quantum optoelectronics.
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Affiliation(s)
- Faji Xie
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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11
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Hou Y, Wang R, Xiao R, McClintock L, Clark Travaglini H, Paulus Francia J, Fetsch H, Erten O, Savrasov SY, Wang B, Rossi A, Vishik I, Rotenberg E, Yu D. Millimetre-long transport of photogenerated carriers in topological insulators. Nat Commun 2019; 10:5723. [PMID: 31844140 PMCID: PMC6915787 DOI: 10.1038/s41467-019-13711-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/21/2019] [Indexed: 11/18/2022] Open
Abstract
Excitons are spin integer particles that are predicted to condense into a coherent quantum state at sufficiently low temperature. Here by using photocurrent imaging we report experimental evidence of formation and efficient transport of non-equilibrium excitons in Bi2-xSbxSe3 nanoribbons. The photocurrent distributions are independent of electric field, indicating that photoexcited electrons and holes form excitons. Remarkably, these excitons can transport over hundreds of micrometers along the topological insulator (TI) nanoribbons before recombination at up to 40 K. The macroscopic transport distance, combined with short carrier lifetime obtained from transient photocurrent measurements, indicates an exciton diffusion coefficient at least 36 m2 s−1, which corresponds to a mobility of 6 × 104 m2 V−1 s−1 at 7 K and is four order of magnitude higher than the value reported for free carriers in TIs. The observation of highly dissipationless exciton transport implies the formation of superfluid-like exciton condensate at the surface of TIs. Exciton condensation may emerge at room temperature in topological materials with strong Coulomb interactions and vanishing electron effective mass. Here, Hou et al. report the formation of excitons in Bi2-xSbxSe3 nanoribbons, which can transport over hundreds of micrometres before recombination up to 40 K, further implying exciton condensation.
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Affiliation(s)
- Yasen Hou
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - Rui Wang
- Department of Physics and Astronomy, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Rui Xiao
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - Luke McClintock
- Department of Physics, University of California, Davis, CA, 95616, USA
| | | | | | - Harry Fetsch
- Department of Physics, Harvey Mudd College, Claremont, CA, 91711, USA
| | - Onur Erten
- Department of Physics, Arizona State University, Tempe, AZ, 85281, USA
| | - Sergey Y Savrasov
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - Baigeng Wang
- Department of Physics, Nanjing University, 210008, Jiangsu, China
| | | | - Inna Vishik
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - Eli Rotenberg
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Dong Yu
- Department of Physics, University of California, Davis, CA, 95616, USA.
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12
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Seifert P, Kundinger M, Shi G, He X, Wu K, Li Y, Holleitner A, Kastl C. Quantized Conductance in Topological Insulators Revealed by the Shockley-Ramo Theorem. PHYSICAL REVIEW LETTERS 2019; 122:146804. [PMID: 31050462 DOI: 10.1103/physrevlett.122.146804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 02/14/2019] [Indexed: 06/09/2023]
Abstract
Crystals with symmetry-protected topological order, such as topological insulators, promise coherent spin and charge transport phenomena even in the presence of disorder at room temperature. We demonstrate how to image and read out the local conductance of helical surface modes in the prototypical topological insulators Bi_{2}Se_{3} and BiSbTe_{3}. We apply the so-called Shockley-Ramo theorem to design an optoelectronic probe circuit for the gapless surface states, and we find a well-defined conductance quantization at 1e^{2}/h within the experimental error without any external magnetic field. The unprecedented response is a clear signature of local spin-polarized transport, and it can be switched on and off via an electrostatic field effect. The macroscopic, global readout scheme is based on an electrostatic coupling from the local excitation spot to the readout electrodes, and it does not require coherent transport between electrodes, in contrast to the conventional Landauer-Büttiker description. It provides a generalizable platform for studying further nontrivial gapless systems such as Weyl semimetals and quantum spin-Hall insulators.
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Affiliation(s)
- Paul Seifert
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Marinus Kundinger
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Gang Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoyue He
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Kehui Wu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yongqing Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Alexander Holleitner
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Christoph Kastl
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
- Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
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13
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Li Y, Zhang D, Lin R, Zhang Z, Zheng W, Huang F. Graphene Interdigital Electrodes for Improving Sensitivity in a Ga 2O 3:Zn Deep-Ultraviolet Photoconductive Detector. ACS APPLIED MATERIALS & INTERFACES 2019; 11:1013-1020. [PMID: 30520294 DOI: 10.1021/acsami.8b14380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Graphene (Gr) has been widely used as a transparent electrode material for photodetectors because of its high conductivity and high transmittance in recent years. However, the current low-efficiency manipulation of Gr has hindered the arraying and practical use of such detectors. We invented a multistep method of accurately tailoring graphene into interdigital electrodes for fabricating a sensitive, stable deep-ultraviolet photodetector based on Zn-doped Ga2O3 films. The fabricated photodetector exhibits a series of excellent performance, including extremely low dark current (∼10-11 A), an ultrahigh photo-to-dark ratio (>105), satisfactory responsivity (1.05 A/W), and excellent selectivity for the deep-ultraviolet band, compared to those with ordinary metal electrodes. The raise of photocurrent and responsivity is attributed to the increase of incident photons through Gr and separated carriers caused by the built-in electric field formed at the interface of Gr and Ga2O3:Zn films. The proposed ideas and methods of tailoring Gr can not only improve the performance of devices but more importantly contribute to the practical development of graphene.
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Affiliation(s)
- Yuqiang Li
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Dan Zhang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Richeng Lin
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Zhaojun Zhang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Wei Zheng
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Feng Huang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials , Sun Yat-sen University , Guangzhou 510275 , P. R. China
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14
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Li M, Wang Z, Yang L, Pan D, Li D, Gao XPA, Zhang Z. Growth and quantum transport properties of vertical Bi 2Se 3 nanoplate films on Si substrates. NANOTECHNOLOGY 2018; 29:315706. [PMID: 29757160 DOI: 10.1088/1361-6528/aac457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Controlling the growth direction (planar versus vertical) and surface-to-bulk ratio can lead to lots of unique properties for two-dimensional layered materials. We report a simple method to fabricate continuous films of vertical Bi2Se3 nanoplates on Si substrate and investigate the quantum transport properties of such films. In contrast to (001) oriented planar Bi2Se3 nanoplate film, vertical Bi2Se3 nanoplate films are enclosed by (015) facets, which possess high surface-to-bulk ratio that can enhance the quantum transport property of topological surface states. And by controlling the compactness of vertical Bi2Se3 nanoplates, we realized an effective tuning of the weak antilocalization effect from topological surface states in Bi2Se3 films. Our work paves a way for exploring the unique transport properties of this unconventional structure topological insulator film.
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Affiliation(s)
- Mingze Li
- National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China. School of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, People's Republic of China
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15
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Seifert P, Vaklinova K, Ganichev S, Kern K, Burghard M, Holleitner AW. Spin Hall photoconductance in a three-dimensional topological insulator at room temperature. Nat Commun 2018; 9:331. [PMID: 29362413 PMCID: PMC5780383 DOI: 10.1038/s41467-017-02671-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/18/2017] [Indexed: 11/29/2022] Open
Abstract
Three-dimensional topological insulators are a class of Dirac materials, wherein strong spin-orbit coupling leads to two-dimensional surface states. The latter feature spin-momentum locking, i.e., each momentum vector is associated with a spin locked perpendicularly to it in the surface plane. While the principal spin generation capability of topological insulators is well established, comparatively little is known about the interaction of the spins with external stimuli like polarized light. We observe a helical, bias-dependent photoconductance at the lateral edges of topological Bi2Te2Se platelets for perpendicular incidence of light. The same edges exhibit also a finite bias-dependent Kerr angle, indicative of spin accumulation induced by a transversal spin Hall effect in the bulk states of the Bi2Te2Se platelets. A symmetry analysis shows that the helical photoconductance is distinct to common longitudinal photoconductance and photocurrent phenomena, but consistent with optically injected spins being transported in the side facets of the platelets. While the spin generation in topological insulators is well studied, little is known about the interaction of the spins with external stimuli. Here, Seifert et al. observe a helical, bias-dependent photoconductance at the lateral edges of topological Bi2Te2Se platelets for perpendicular incidence of light, distinct to common longitudinal photoconductance phenomena.
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Affiliation(s)
- Paul Seifert
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4a, D-85748, Garching, Germany
| | - Kristina Vaklinova
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
| | - Sergey Ganichev
- Terahertz Center, University of Regensburg, D-93040, Regensburg, Germany
| | - Klaus Kern
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany.,Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Marko Burghard
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
| | - Alexander W Holleitner
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4a, D-85748, Garching, Germany.
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