Photovoltaic Field-Effect Photodiodes Based on Double van der Waals Heterojunctions.

High performance photodetectors based on van der Waals heterostructures (vdWHs) are crucial to developing micro-nano-optoelectronic devices. However, reports show that it is difficult to balance fast response and high sensitivity. In this work, we design a photovoltaic field-effect photodiode (PVFED) based on the WSe2/MoS2/WSe2 double vdWHs, where the photovoltage that originated from one vdWH modulates the optoelectronic characteristics of another vdWH. The proposed photodiode exhibits an excellent self-powered ability with a high responsivity of 715 mA·W-1 and fast response time of 45 μs. This work demonstrates an efficient method that optimizes the photoelectric performance of vdWH by introducing the photovoltaic field effect.