A Broadband Fluorographene Photodetector

• DOI: 10.1002/adma.201700463
• Publication Date: 2017-04-05T15:50:34Z
• Authors: Sichao Du; Wei Lu; Ayaz Ali; Pei Zhao; Khurram Shehzad; Hongwei Guo; Lingling Ma; Xuemei Liu; Xiaodong Pi; Peng Wang; Hehai Fang; Zhen Xu; Chao Gao; Yaping Dan; Pingheng Tan; Hongtao Wang; Cheng‐Te Lin; Jianyi Yang; Shurong Dong; Zhiyuan Cheng; Erping Li; Wenyan Yin; Jikui Luo; Bin Yu; Tawfique Hasan; Yang Xu; Weida Hu; Xiangfeng Duan
• Keywords: fluorographene; mid-infrared; 02 engineering and technology; 7. Clean energy; Engineering; midâ infrared; Materials Science and Engineering; ultraviolet; Engineering (General); photodetectors; broadband; 0210 nano-technology

High‐performance photodetectors operating over a broad wavelength range from ultraviolet, visible, to infrared are of scientific and technological importance for a wide range of applications. Here, a photodetector based on van der Waals heterostructures of graphene and its fluorine‐functionalized derivative is presented. It consistently shows broadband photoresponse from the ultraviolet (255 nm) to the mid‐infrared (4.3 µm) wavelengths, with three orders of magnitude enhanced responsivity compared to pristine graphene photodetectors. The broadband photodetection is attributed to the synergistic effects of the spatial nonuniform collective quantum confinement of sp2 domains, and the trapping of photoexcited charge carriers in the localized states in sp3 domains. Tunable photoresponse is achieved by controlling the nature of sp3 sites and the size and fraction of sp3/sp2 domains. In addition, the photoresponse due to the different photoexcited‐charge‐carrier trapping times in sp2 and sp3 nanodomains is determined. The proposed scheme paves the way toward implementing high‐performance broadband graphene‐based photodetectors.