Enhanced photosensitivity in a hybrid WSe2/2DEG heterojunction using a buried TiO2 photosensitive layer

Abstract

In this study, we integrated the wide-bandgap material TiO2 as a photosensitive layer with the WSe2/2DEG heterostructure, creating a hybrid WSe2/TiO2/2DEG heterojunction. This hybrid structure significantly improves the device’s photosensitivity, exhibiting a high rectification effect and a switching ratio of 103. The photodetector shows excellent performance, with a responsivity of 0.61 A W−1 and a detectivity of up to 1.1×1011 Jones at 405 nm, along with a very fast photoresponse speed. The buried TiO2 channel allows photogenerated electrons to easily flow through the reduced barrier at the depleted region. This hybrid heterojunction holds promise for the development of high-performance photoelectric devices.