Duan Research Group

Hetero-integrated Nanostructures and Nanodevices


A self-powered high-performance graphene/silicon ultraviolet photodetector with ultra-shallow junction: breaking the limit of silicon? npj 2D Mater

Xia Wan, Yang Xu, Hongwei Guo, Khurram Shehzad, Ayaz Ali, Yuan Liu, Jianyi Yang, Daoxin Dai, Cheng-Te Lin, Liwei Liu, Hung-Chieh Cheng, Fengqiu Wang, Xiaomu Wang, Hai Lu, Weida Hu, Xiaodong Pi, Yaping Dan, Jikui Luo, Tawfique Hasan, Xiangfeng Duan, Xinming Li, Jianbin Xu, Deren Yang, Tianling Ren, Bin Yu

npj 2D Materials and Applications 1, 4 (2017)

We present a self-powered, high-performance graphene-enhanced ultraviolet silicon Schottky photodetector. Different from traditional transparent electrodes, such as indium tin oxides or ultra-thin metals, the unique ultraviolet absorption property of graphene leads to long carrier life time of hot electrons that can contribute to the photocurrent or potential carrier-multiplication. Our proposed structure boosts the internal quantum efficiency over 100%, approaching the upper-limit of silicon-based ultraviolet photodetector. In the near-ultraviolet and mid-ultraviolet spectral region, the proposed ultraviolet photodetector exhibits high performance at zero-biasing (self-powered) mode, including high photo-responsivity (0.2 A W−1), fast time response (5 ns), high specific detectivity (1.6 × 1013 Jones), and internal quantum efficiency greater than 100%. Further, the photo-responsivity is larger than 0.14 A W−1 in wavelength range from 200 to 400 nm, comparable to that of state-of-the-art Si, GaN, SiC Schottky photodetectors. The photodetectors exhibit stable operations in the ambient condition even 2 years after fabrication, showing great potential in practical applications, such as wearable devices, communication, and “dissipation-less” remote sensor networks.
UCLA, Department of Chemistry and Biochemistry
607 Charles E. Young Drive East, Box 951569
Los Angeles, CA 90095-1569
E-mail: xduan@chem.ucla.edu