Highly stable semitransparent multilayer graphene/LaVO₃vertical-heterostructure photodetectors

A heterostructure composed of a combination of semi-metallic graphene (Gr) and high-absorption LaVO₃is ideal for high-performance translucent photodetector (PD) applications. Here, we present multilayer Gr/LaVO₃vertical-heterostructure semitransparent PDs with various layer numbers (L_n). AtL_n= 2, the PD shows the best performance with a responsivity (R) of 0.094 A W^-1and a specific detectivity (D*) of 7.385 × 10⁷cm Hz^1/2W^-1at 532 nm. Additionally, the average visible transmittance of the PD is 63%, i.e. it is semitransparent. We increased photocurrent (PC) by approximately 13%, from 0.564 to 0.635μA cm^-2by using an Al reflector on the semitransparent PD. The PC of an unencapsulated PD maintains about 86% (from 0.571 to 0.493μA cm^-2) of its initial PC value after 2000 h at 25 °C temperature/30% relative humidity, showing good stability. This behavior is superior to that of previously reported graphene-based PDs. These results show that these PDs have great potential for semitransparent optoelectronic applications.