Electrically Stimulated Band Alignment Transit in Black Phosphorus/β-Ga2O3 Heterostructure Dual-band Photodetector

In recent decades,dual-band photodetectors have received widespread attention due to better target iden-tification,which are considered as the development trend of next generation photodetectors.However,the traditional dual-band photodetectors based on heteroepitaxial growth,superlattice and multiple quantum well structures are limited by complex fabrication process and low integration.Herein,we report a UV/IR dual-band photodetector by integrating ultra-wide gap B-Ga2O,and narrow-gap black phosphorous(BP)nanoflakes.A vertical van der Waals(vdW)heterostructure is formed between BP and B-Ga,O,by mechanically exfoliated method integrated without the requirement of lattice match.The heterostructure devices show excellent rectification characteristics with high recti-fving ratio of ca.10 and low reverse current around pA.Moreover,the device displays obvious photoresponse underUV and IR irradiations with responsivities of 0.87 and 2.15 mA/W,respectively.We also explore the band alignment transit within the heterostructure photodetector at different bias voltages.This work paves the way for fabricating novel dual-band photodetectors by utilizing 2D materials.