Self-powered semitransparent WS₂/LaVO₃ vertical-heterostructure photodetectors by employing interfacial hexagonal boron nitride

Abstract

Two-dimensional (2D) semiconductor and LaVO3 materials with high absorption coefficients in the visible light region are attractive structures for high-performance photodetector (PD) applications. Insulating 2D hexagonal boron nitride (h-BN) with a large band gap and excellent transmittance is a very attractive material as an interface between 2D/semiconductor heterostructures. We first introduce WS2/h-BN/LaVO3 PD. The photo-current/dark current ratio of the device exhibits a delta-function characteristic of 4 x 105 at 0 V, meaning "self-powered". The WS2/h-BN/LaVO3 PD shows up to 0.27 AW-1 responsivity (R) and 4.6 x 1010 cm Hz1/2 W-1 detectivity (D*) at 730 nm. Especially, it was confirmed that the D* performance improved by about 5 times compared to the WS2/LaVO3 device at zero bias. Additionally, it is suggested that the PD maintains 87 % of its initial R for 2000 h under an atmosphere with a temperature of 25°C and humidity of 30 %. Based on the above results, we suggest that the WS2/h-BN/LaVO3 heterojunction is promising as a self-powered optoelectronic device.