A field-effect WSe ₂/Si heterojunction diode

It is significant to develop a heterogeneous integration technology to promote the application of two-dimensional (2D) materials in silicon roadmap. In this paper, we reported a field-effect WSe ₂/Si heterojunction diode based on ambipolar 2D WSe ₂ and silicon on insulator (SOI). Our results indicate that the device exhibits a p–n diode behavior with a rectifying ratio of ∼ 300 and an ideality factor of 1.37. As a photodetector, it has optoelectronic properties with a response time of 0.13 ms, responsivity of 0.045 A/W, detectivity of 4.5×10 ¹⁰ Jones and external quantum efficiency (EQE) of 8.9 %. Due to the ambipolar behavior of the WSe ₂, the rectifying and optoelectronic properties of the heterojunction diode can be modulated by the gate electrical field, enabling various potential applications such as logic optoelectronic devices and neuromorphic optoelectronic devices for in-sensor computing circuits. Thanks to the process based on the mature SOI technique, our field-effect heterojunction diode should have obvious advantages in device isolation and integration.