High-efficiency omnidirectional photoresponses based on monolayer lateral p-n heterojunctions

Electrical and optical properties of lateral monolayer WSe2-MoS2 p-n heterojunctions were characterized to demonstrate a high responsivity of 0.26 A W-1 with an excellent omnidirectional photodetection capability. The heterojunction functioning as a diode exhibits a prominent gate-tuning behavior with an ideality factor of 1.25. In addition, ultrafast photoresponse, low-light detectability, and high-temperature operation have been achieved. These unique characteristics pave a way for the future development of sub-nano semiconductor devices.