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

In this study, we integrated the wide-bandgap material TiO 2 as a photosensitive layer with the WSe 2 /2DEG heterostructure, creating a hybrid WSe 2 /TiO 2 /2DEG heterojunction. This hybrid structure significantly improves the device’s photosensitivity, exhibiting a high rectification effect and a switching ratio of 10 3 . The photodetector shows excellent performance, with a responsivity of 0.61 A W −1 and a detectivity of up to 1.1×10 11 Jones at 405 nm, along with a very fast photoresponse speed. The buried TiO 2 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.