• 文献标题:   Highly Enhanced SWIR Image Sensors Based on Ge1-xSnx-Graphene Heterostructure Photodetector
  • 文献类型:   Article
  • 作  者:   YANG F, YU K, CONG H, XUE CL, CHENG BW, WANG N, ZHOU L, LIU Z, WANG QM
  • 作者关键词:   silicon photonic, hybrid structure, germaniumtin, photodetector array, graphene, infrared
  • 出版物名称:   ACS PHOTONICS
  • ISSN:   2330-4022
  • 通讯作者地址:   Chinese Acad Sci
  • 被引频次:   11
  • DOI:   10.1021/acsphotonics.8b01731
  • 出版年:   2019

▎ 摘  要

Ge1-xSnx with a tunable bandgap that covers full shortwave infrared (SWIR) from 1 to 2.6 mu m presents a new paradigm for silicon-based SWIR photodetection. However, low absorption and high surface recombination remain to be large limitations for realization of high performance photodetector. This work demonstrates GeSn-graphene heterostructure photo-detectors with high responsivity, photoconductive gain, and detectivity can effectively lessen the burdens. Compared with the pure GeSn photodetector, the introduction of graphene not only effectively solves the problem of serious surface states of the GeSn active layer, but achieves large enhancements in both photo-current and response speed, even under a relatively weak illumination, which indicates photogenerated carriers can be separated and transported in higher efficiency. At the same time, there is no recession in performance after a 4 month exposure in ambient environment. In addition, the heterostructure is integrated into a 20 x 20 pixel detector array with a size of 440 x 440 mu m(2) and an image of letter "E" is clearly obtained according to a mask measurement method. The compatibility with CMOS technique offers such photodetector new opportunities for application in SWIR optical communication and imaging, remote sensing, and biomedical.