Broadband polarized photodetector based on p-BP/n-ReS2 heterojunction

Two-dimensional (2D) atomic crystals, such as graphene, black phosphorus (BP) and transition metal dichalcogenides (TMDCs) are attractive for use in optoelectronic devices, due to their unique crystal structures and optical absorption properties. In this study, we fabricated BP/ReS2 van der Waals (vdWs) heterojunction devices. The devices realized broadband photoresponse from visible to near infrared (NIR) (400-1800 nm) with stable and repeatable photoswitch characteristics, and the photoresponsivity reached 1.8 mA/W at 1550 nm. In addition, the polarization sensitive detection in the visible to NIR spectrum (532-1750 nm) was demonstrated, and the photodetector showed a highly polarization sensitive photocurrent with an anisotropy ratio as high as 6.44 at 1064 nm. Our study shows that van der Waals heterojunction is an effective way to realize the broadband polarization sensitive photodetection, which is of great significance to the realization and application of multi-functional devices based on 2D vdWs heterostructures.