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Kim E, Hwang G, Kim D, Won D, Joo Y, Zheng S, Watanabe K, Taniguchi T, Moon P, Kim DW, Sun L, Yang H. Orbital Gating Driven by Giant Stark Effect in Tunneling Phototransistors. Adv Mater 2022; 34:e2106625. [PMID: 34825405 DOI: 10.1002/adma.202106625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/15/2021] [Indexed: 06/13/2023]
Abstract
Conventional gating in transistors uses electric fields through external dielectrics that require complex fabrication processes. Various optoelectronic devices deploy photogating by electric fields from trapped charges in neighbor nanoparticles or dielectrics under light illumination. Orbital gating driven by giant Stark effect is demonstrated in tunneling phototransistors based on 2H-MoTe2 without using external gating bias or slow charge trapping dynamics in photogating. The original self-gating by light illumination modulates the interlayer potential gradient by switching on and off the giant Stark effect where the dz 2-orbitals of molybdenum atoms play the dominant role. The orbital gating shifts the electronic bands of the top atomic layer of the MoTe2 by up to 100 meV, which is equivalent to modulation of a carrier density of 7.3 × 1011 cm-2 by electrical gating. Suppressing conventional photoconductivity, the orbital gating in tunneling phototransistors achieves low dark current, practical photoresponsivity (3357 AW-1 ), and fast switching time (0.5 ms) simultaneously.
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Affiliation(s)
- Eunah Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Geunwoo Hwang
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Dohyun Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Dongyeun Won
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Yanggeun Joo
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Shoujun Zheng
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 303-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 303-0044, Japan
| | - Pilkyung Moon
- York University Shanghai and NYU-ECNU Institute of Physics at NYU Shanghai, Shanghai, 200122, China
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, 02455, Korea
| | - Dong-Wook Kim
- Department of Physics, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Korea
| | - Linfeng Sun
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
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Zheng S, Jo S, Kang K, Sun L, Zhao M, Watanabe K, Taniguchi T, Moon P, Myoung N, Yang H. Resonant Tunneling Spectroscopy to Probe the Giant Stark Effect in Atomically Thin Materials. Adv Mater 2020; 32:e1906942. [PMID: 32027062 DOI: 10.1002/adma.201906942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/13/2019] [Indexed: 06/10/2023]
Abstract
Each atomic layer in van der Waals heterostructures possesses a distinct electronic band structure that can be manipulated for unique device operations. In the precise device architecture, the subtle but critical band splits by the giant Stark effect between atomic layers, varied by the momentum of electrons and external electric fields in device operation, has not yet been demonstrated or applied to design original devices with the full potential of atomically thin materials. Here, resonant tunneling spectroscopy based on the negligible quantum capacitance of 2D semiconductors in resonant tunneling transistors is reported. The bandgaps and sub-band structures of various channel materials could be demonstrated by the new conceptual spectroscopy at the device scale without debatable quasiparticle effects. Moreover, the band splits by the giant Stark effect in the channel materials could be probed, overcoming the limitations of conventional optical, photoemission, and tunneling spectroscopy. The resonant tunneling spectroscopy reveals essential and practical information for novel device applications.
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Affiliation(s)
- Shoujun Zheng
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Sanghyun Jo
- Samsung Advanced Institute of Technology, Suwon, 16678, Korea
| | - Kyungrok Kang
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Linfeng Sun
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Mali Zhao
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Pilkyung Moon
- New York University Shanghai and NYU-ECNU Institute of Physics at NYU Shanghai, Shanghai, 200122, China
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200122, China
| | - Nojoon Myoung
- Department of Physics Education, Chosun University, Gwangju, 61452, Korea
| | - Heejun Yang
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
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Tian XQ, Wang XR, Wei YD, Liu L, Gong ZR, Gu J, Du Y, Yakobson BI. Highly Tunable Electronic Structures of Phosphorene/Carbon Nanotube Heterostructures through External Electric Field and Atomic Intercalation. Nano Lett 2017; 17:7995-8004. [PMID: 29191020 DOI: 10.1021/acs.nanolett.7b04562] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Black phosphorene (BP)/carbon nanotube (CNT) heterostructures can be classified as either type I or II, depending on the size of the CNTs. An external electric field (Eext) can modulate the interfacial electronic structures and separate the electron and hole carriers of the BP/CNT heterostructures. The giant Stark effect is observed, and the band gap of the semiconducting heterostructures can vary several-fold. The intercalation of 3d transition metals can strongly bond BP and CNTs together. Furthermore, strong ferromagnetism with Curie temperature (TC) above room temperature is predicted. It is expected that these BP/CNT heterostructures will provide new opportunities and applications in the fields of optoelectronics and electronics as well as spintronics.
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Affiliation(s)
- Xiao-Qing Tian
- College of Physics and Energy, Shenzhen University , Shenzhen 518060, Guangdong, P.R. China
- Department of Physics, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong
| | - Xiang-Rong Wang
- Department of Physics, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong
- HKUST Shenzhen Research Institute , Shenzhen 518057, China
| | - Ya-Dong Wei
- College of Physics and Energy, Shenzhen University , Shenzhen 518060, Guangdong, P.R. China
| | - Lin Liu
- College of Physics and Energy, Shenzhen University , Shenzhen 518060, Guangdong, P.R. China
| | - Zhi-Rui Gong
- College of Physics and Energy, Shenzhen University , Shenzhen 518060, Guangdong, P.R. China
| | - Juan Gu
- College of Physics and Energy, Shenzhen University , Shenzhen 518060, Guangdong, P.R. China
| | - Yu Du
- College of Physics and Energy, Shenzhen University , Shenzhen 518060, Guangdong, P.R. China
| | - Boris I Yakobson
- Department of Materials Science and NanoEngineering, Department of Chemistry, and the Smalley Institute for Nanoscale Science and Technology, Rice University , Houston, Texas 77005, United States
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Liu Y, Qiu Z, Carvalho A, Bao Y, Xu H, Tan SJR, Liu W, Castro Neto AH, Loh KP, Lu J. Gate-Tunable Giant Stark Effect in Few-Layer Black Phosphorus. Nano Lett 2017; 17:1970-1977. [PMID: 28195492 DOI: 10.1021/acs.nanolett.6b05381] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Two-dimensional black phosphorus (BP) has sparked enormous research interest due to its high carrier mobility, layer-dependent direct bandgap and outstanding in-plane anisotropic properties. BP is one of the few two-dimensional materials where it is possible to tune the bandgap over a wide energy range from the visible up to the infrared. In this article, we report the observation of a giant Stark effect in electrostatically gated few-layer BP. Using low-temperature scanning tunnelling microscopy, we observed that in few-layer BP, when electrons are injected, a monotonic reduction of the bandgap occurs. The injected electrons compensate the existing defect-induced holes and achieve up to 35.5% bandgap modulation in the light-doping regime. When probed by tunnelling spectroscopy, the local density of states in few-layer BP shows characteristic resonance features arising from layer-dependent sub-band structures due to quantum confinement effects. The demonstration of an electrical gate-controlled giant Stark effect in BP paves the way to designing electro-optic modulators and photodetector devices that can be operated in a wide electromagnetic spectral range.
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Affiliation(s)
- Yanpeng Liu
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
| | - Zhizhan Qiu
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore , 28 Medical Drive, Singapore 117456
| | - Alexandra Carvalho
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
- Department of Physics, National University of Singapore , 3 Science Drive 2, Singapore 117542
| | - Yang Bao
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
| | - Hai Xu
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
| | - Sherman J R Tan
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore , 28 Medical Drive, Singapore 117456
| | - Wei Liu
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
| | - A H Castro Neto
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
- Department of Physics, National University of Singapore , 3 Science Drive 2, Singapore 117542
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
| | - Jiong Lu
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , Singapore 117546
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Kang M, Kim B, Ryu SH, Jung SW, Kim J, Moreschini L, Jozwiak C, Rotenberg E, Bostwick A, Kim KS. Universal Mechanism of Band-Gap Engineering in Transition-Metal Dichalcogenides. Nano Lett 2017; 17:1610-1615. [PMID: 28118710 DOI: 10.1021/acs.nanolett.6b04775] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
van der Waals two-dimensional (2D) semiconductors have emerged as a class of materials with promising device characteristics owing to the intrinsic band gap. For realistic applications, the ideal is to modify the band gap in a controlled manner by a mechanism that can be generally applied to this class of materials. Here, we report the observation of a universally tunable band gap in the family of bulk 2H transition metal dichalcogenides (TMDs) by in situ surface doping of Rb atoms. A series of angle-resolved photoemission spectra unexceptionally shows that the band gap of TMDs at the zone corners is modulated in the range of 0.8-2.0 eV, which covers a wide spectral range from visible to near-infrared, with a tendency from indirect to direct band gap. A key clue to understanding the mechanism of this band-gap engineering is provided by the spectroscopic signature of symmetry breaking and resultant spin-splitting, which can be explained by the formation of 2D electric dipole layers within the surface bilayer of TMDs. Our results establish the surface Stark effect as a universal mechanism of band-gap engineering on the basis of the strong 2D nature of van der Waals semiconductors.
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Affiliation(s)
- Mingu Kang
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
| | - Beomyoung Kim
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Sae Hee Ryu
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
| | - Sung Won Jung
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
| | - Jimin Kim
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
| | - Luca Moreschini
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Chris Jozwiak
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Eli Rotenberg
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Aaron Bostwick
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Keun Su Kim
- Department of Physics, Pohang University of Science and Technology , Pohang 37673, Korea
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Woo J, Yun KH, Chung YC. Graphene Monoxide Bilayer As a High-Performance on/off Switching Media for Nanoelectronics. ACS Appl Mater Interfaces 2016; 8:10477-10482. [PMID: 27046262 DOI: 10.1021/acsami.6b01772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The geometries and electronic characteristics of the graphene monoxide (GMO) bilayer are predicted via density functional theory (DFT) calculations. All the possible sequences of the GMO bilayer show the typical interlayer bonding characteristics of two-dimensional bilayer systems with a weak van der Waals interaction. The band gap energies of the GMO bilayers are predicted to be adequate for electronic device application, indicating slightly smaller energy gaps (0.418-0.448 eV) compared to the energy gap of the monolayer (0.536 eV). Above all, in light of the band gap engineering, the band gap of the GMO bilayer responds to the external electric field sensitively. As a result, a semiconductor-metal transition occurs at a small critical electric field (EC = 0.22-0.30 V/Å). It is therefore confirmed that the GMO bilayer is a strong candidate for nanoelectronics.
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Affiliation(s)
- Jungwook Woo
- Department of Materials Science and Engineering, Hanyang University , 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Kyung-Han Yun
- Department of Materials Science and Engineering, Hanyang University , 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Yong-Chae Chung
- Department of Materials Science and Engineering, Hanyang University , 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
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Abstract
We report a new two-dimensional hexagonal beryllium sulfide (h-BeS) sheet with exceptional properties by extensive first-principles calculations. The h-BeS sheet presents an indirect energy gap of 4.26 eV and an outstanding thermodynamic stability up to 1000 K. Armchair-edged nanoribbons of h-BeS are wide-energy-gap semiconductors with a giant Stark effect, while the zigzag-edged ones are metals with spin glass state. Especially, the ferromagnetic zigzag nanoribbons exhibit a net magnetic moment of nearly 1.15 μB. These interesting electronic and magnetic properties suggest the promise of the h-BeS crystal for potential applications and should inspire experimental enthusiasm.
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Affiliation(s)
- Jin Yu
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Key Laboratory for Intelligent Nano Materials and Devices of MOE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Wanlin Guo
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Key Laboratory for Intelligent Nano Materials and Devices of MOE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
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