High‐Responsivity Graphene/InAs Nanowire Heterojunction Near‐Infrared Photodetectors with Distinct Photocurrent On/Off Ratios. Issue 8 (31st October 2014)

• Record Type: Journal Article
• Authors: Miao, Jinshui; Hu, Weida; Guo, Nan; Lu, Zhenyu; Liu, Xingqiang; Liao, Lei; Chen, Pingping; Jiang, Tao; Wu, Shiwei; Ho, Johnny C.; Wang, Lin; Chen, Xiaoshuang; Lu, Wei
• Is Part Of: Small. Volume 11:Issue 8(2015)
• Page Start: 936
• Page End: 942
• Publication Date: 2014-10-31
• Subjects: Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201402312
• Languages: English
• ISSNs: 1613-6810

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Graphene is a promising candidate material for high‐speed and ultra‐broadband photodetectors. However, graphene‐based photodetectors suffer from low photoreponsivity and <italic>I_light/I_dark</italic> 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 <italic>I_light/I_dark</italic> ratio of 5 × 10², while the photoresponsivity and <italic>I_light/I_dark</italic> ratio of graphene infrared photodetectors are 0.1 mAW⁻¹ and 1, respectively. The Fermi level (<italic>E_F</italic>) 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.</p> </abstract>