Locally hydrazine doped WSe₂ p-n junction toward high-performance photodetectors

Two dimensional (2D) materials have shown great potential in the photodetection and other optoelectronic applications. Exploiting 2D materials to form p-n junctions enables effective generation and separation of carriers excited by light, thus creating high-performance optoelectronic devices. This paper demonstrates a lateral WSe₂ p-n junction through a locally hydrazine doping method. Good current-rectifying characteristics, including a high rectification ratio of ∼10³, have been observed; this indicates that a high-quality p-n junction has been formed by chemical doping. Under light illumination, the device shows improved photoresponse capabilities with a responsivity of 30 mA W^-1, a detectivity of 6.18 ×10⁸ Jones, photocurrent/dark current ratio of 10³ and a response time of 2 ms. These results suggest an effective way to get a p-n junction and reveal the application potential of the device for next generation photodetectors.