Two-dimensional transition metal dichalcogenides are emerging with tremendous potential in many optoelectronic applications due to their strong light-matter interactions. To fully explore their potential in photoconductive detectors, high responsivity and weak signal detection are required. Here, we present high responsivity phototransistors based on few-layer rhenium disulfide (ReS2). Depending on the back gate voltage, source drain bias and incident optical light intensity, the maximum attainable photoresponsivity can reach as high as 88,600 A W-1, which is a record value compared to other two-dimensional materials with similar device structures and two orders of magnitude higher than that of monolayer MoS2. Such high photoresponsivity is attributed to the increased light absorption as well as the gain enhancement due to the existence of trap states in the few-layer ReS2 flakes. It further enables the detection of weak signals, as successfully demonstrated with weak light sources including a lighter and limited fluorescent lighting. Our studies underscore ReS2 as a promising material for future sensitive optoelectronic applications.
@article{arxiv.1512.06515,
title = {High responsivity phototransistors based on few-layer ReS2 for weak signal detection},
author = {Erfu Liu and Mingsheng Long and Junwen Zeng and Wei Luo and Yaojia Wang and Yiming Pan and Wei Zhou and Baigeng Wang and Weida Hu and Zhenhua Ni and Yumeng You and Xueao Zhang and Shiqiao Qin and Yi Shi and K. Watanabe and T. Taniguchi and Hongtao Yuan and Harold Y. Hwang and Yi Cui and Feng Miao and Dingyu Xing},
journal= {arXiv preprint arXiv:1512.06515},
year = {2017}
}