High-performance self-powered ultraviolet to near-infrared photodetector based on WS2/InSe van der Waals heterostructure
Jinping Chen, Zhen Zhang, Yi Ma, Jiying Feng, Xiaoyu Xie, Xiaoxuan Wang, Aoqun Jian, Yuanzheng Li, Zhuxin Li, Heng Guo, Yizhi Zhu, Qiannan Cui, Zengliang Shi, Chunxiang Xu
Abstract
van der Waals heterostructures (vdWHs) based on two-dimensional (2D) materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices. Herein, a WS2/InSe vdWH photodiode is proposed and fabricated by precisely stacking InSe and WS2 flakes through an all-dry transfer method. The WS2/InSe vdWH forms an n—n heterojunction with strong built-in electric field due to their intrinsic n-type semiconductor characteristics and energy-band alignments with a large Fermi level offset between WS2 and InSe. As a result, the device displays excellent photovoltaic behavior with a large open voltage of 0.47 V and a short-circuit current of 11.7 nA under 520 nm light illumination. Significantly, a fast rising/decay time of 63/76 µs, a large light on/off ratio of 105, a responsivity of 61 mA/W, a high detectivity of 2.5 × 1011 Jones, and a broadband photoresponse ranging from ultraviolet to near-infrared (325–980 nm) are achieved at zero bias. This study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.