Graphene/SrTiO3 interface-based UV photodetectors with high responsivity  

作　　者：Heng Yue Anqi Hu Qiaoli Liu Huijun Tian Chengri Hu Xiansong Ren Nianyu Chen Chen Ge Kuijuan Jin Xia Guo 岳恒;胡安琪;刘巧莉;田慧军;胡成日;任显松;陈年域;葛琛;金奎娟;郭霞(State Key Laboratory for Information Photonics and Optical Communications,School of Electronic Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]State Key Laboratory for Information Photonics and Optical Communications,School of Electronic Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,China [2]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Chinese Physics B》2021年第3期540-545,共6页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFF0104801 and 2018YFB0406601);the National Natural Science Foundation of China(Grant Nos.61804012 and 11721404).

摘　　要：Strontium titanate(SrTiO3),which is a crucial perovskite oxide with a direct energy band gap of 3.2 eV,holds great promise for ultraviolet(UV)photodetection.However,the response performance of the conventional SrTiO3-based photodetectors is limited by the large relative dielectric constant of the material,which reduces the internal electric field for electron-hole pair separation to form a current collected by electrodes.Recently,graphene/semiconductor hybrid photodetectors by van-der-Waals heteroepitaxy method demonstrate ultrahigh sensitivity,which is benefit from the interface junction architecture and then prolonged lifetime of photoexcited carriers.Here,a graphene/SrTiO3 interface-based photodetector is demonstrated with an ultrahigh responsivity of 1.2×106 A/W at the wavelength of 325 nm and∼2.4×104 A/W at 261 nm.The corresponding response time is in the order of∼ms.Compared with graphene/GaN interface junctionbased hybrid photodetectors,∼2 orders of magnitude improvement of the ultrahigh responsivity originates from a gain mechanism which correlates with the large work function difference induced long photo-carrier lifetime as well as the low background carrier density.The performance of high responsivity and fast response speed facilitates SrTiO3 material for further efforts seeking practical applications.

关 键 词：INTERFACE SRTIO3 ultraviolet photodetector high responsivity 

分 类 号：TN36[电子电信—物理电子学] TN23