High‐Responsivity Graphene/InAs Nanowire Heterojunction Near‐Infrared Photodetectors with Distinct Photocurrent On/Off Ratios |
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Authors: | Jinshui Miao Weida Hu Nan Guo Zhenyu Lu Xingqiang Liu Lei Liao Pingping Chen Tao Jiang Shiwei Wu Johnny C Ho Lin Wang Xiaoshuang Chen Wei Lu |
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Affiliation: | 1. National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, China;2. Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, China;3. Department of Physics and Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of Education, Wuhan University, Wuhan, China;4. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, China;5. Department of Physics and Materials Science, City University of Hong Kong, SAR, China |
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Abstract: | Graphene is a promising candidate material for high‐speed and ultra‐broadband photodetectors. However, graphene‐based photodetectors suffer from low photoreponsivity and Ilight/Idark ratios due to their negligible‐gap nature and small optical absorption. Here, a new type of graphene/InAs nanowire (NW) vertically stacked heterojunction infrared photodetector is reported, with a large photoresponsivity of 0.5 AW?1 and Ilight/Idark ratio of 5 × 102, while the photoresponsivity and Ilight/Idark ratio of graphene infrared photodetectors are 0.1 mAW?1 and 1, respectively. The Fermi level (EF ) of graphene can be widely tuned by the gate voltage owing to its 2D nature. As a result, the back‐gated bias can modulate the Schottky barrier (SB) height at the interface between graphene and InAs NWs. Simulations further demonstrate the rectification behavior of graphene/InAs NW heterojunctions and the tunable SB controls charge transport across the vertically stacked heterostructure. The results address key challenges for graphene‐based infrared detectors, and are promising for the development of graphene electronic and optoelectronic applications. |
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Keywords: | graphene InAs nanowires heterojunctions infrared photodetectors |
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