Self-powered photodetectors with high detectivity based on MoSe2/Si heterojunction using ITO as the transparent electrode and highlight trapping structures

Abstract

Due to the remarkable light absorption effect and electrical properties, transition metal dichalcogenide-based heterojunction allows for the realization of a highly sensitive photodetector. A self-powered photodetector with high detectivity (355–980 nm) was reported based on the MoSe2 that was prepared by the MoO3 films as the precursor layer which reduced the reaction temperature. The n-type silicon substrates with optical trapping structures were prepared by wet chemistry, which can enhance the performance of photodetectors. The as-grown MoSe2 nanosheet was applied in the self-powered ITO/MoSe2/Si photodetector. The self-powered device can detect faint light with a power density below 200 μW/cm2 which shows high responsivity (18.13 mA/W), normalized detectivity (2.80 × 1012 cm·HZ1/2W−1) and a fast response time of 43 ms under 980 nm (1.5 mW/cm2) illumination at zero bias. The ITO/MoSe2/ Si heterojunction with outstanding properties has promising potential for application in self-powered, sensitive, and broadband photodetectors.