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.