Te nanomesh-monolayer WSe2 vertical van der Waals heterostructure for high-performance photodetector

Recently, two-dimensional tungsten diselenide (WSe2) has attracted extensive attention due to their unique properties, exhibiting excellent properties in electronics, optoelectronics, and valleytronics. However, the limited light absorption efficiency of monolayer WSe2 severely hinders its practical applications. To address this challenge, vertical Te-WSe2 heterojunctions consisting of Te nanomesh and monolayer WSe2 nanofilm have been prepared using the two-step vapor deposition method, which significantly enhances the optoelectronic performance. Te-WSe2 heterojunction photodetector exhibits a high responsivity of 1.3 A/W and a specific detectivity of 1 × 1010 Jones under the irradiation of 460 nm light source. This study demonstrates the controllable fabrication of large-scale of Te-WSe2 vertical heterojunctions. The underlying mechanism for the performance enhancement of Te-WSe2 heterojunction photodetector was elucidated based on the Ohm-like type-I band-aligned structure. The research can be further extended to other Te-based mixed-dimensional heterojunctions, providing valuable theoretical and experimental support for the application of next-generation integrated optoelectronic devices.