Van der Waals junctions of two-dimensional materials with an atomically sharp interface open up unprecedented opportunities to design and study functional heterostructures. Semiconducting transition metal dichalcogenides have shown tremendous potential for future applications due to their unique electronic properties and strong light-matter interaction. However, many important optoelectronic applications, such as broadband photodetection, are severely hindered by their limited spectral range and reduced light absorption. Here, we present a p-g-n heterostructure formed by sandwiching graphene with a gapless bandstructure and wide absorption spectrum in an atomically thin p-n junction to overcome these major limitations. We have successfully demonstrated a MoS2-graphene-WSe2 heterostructure for broadband photodetection in the visible to short-wavelength infrared range at room temperature that exhibits competitive device performance, including a specific detectivity of up to 1011 Jones in the near-infrared region. Our results pave the way toward the implementation of atomically thin heterostructures for broadband and sensitive optoelectronic applications.
@article{arxiv.1601.01814,
title = {Broadband Photovoltaic Detectors based on an Atomically Thin Heterostructure},
author = {Mingsheng Long and Erfu Liu and Peng Wang and Anyuan Gao and Wei Luo and Baigeng Wang and Junwen Zeng and Yajun Fu and Kang Xu and Wei Zhou and Yangyang Lv and Shuhua Yao and Minghui Lu and Yanfeng Chen and Zhenhua Ni and Yumeng You and Xueao Zhang and Shiqiao Qin and Yi Shi and Weida Hu and Dingyu Xing and Feng Miao},
journal= {arXiv preprint arXiv:1601.01814},
year = {2017}
}