Pulsed laser deposition for conformal growth of MoS2 on GaN nanorods for highly efficient self-powered photodetection

Abstract

Nanostructure-based photodetectors (PDs) have recently attracted intensive attention due to their immense potential in high performance next-generation photonic devices. Herein, we report a self-powered, ultrafast and broadband PD based on conformally grown MoS₂ on GaN nanorods (NRs). The higher aspect-ratio and extensively exposed edges of conformal 2D materials provide a large interface for better optical absorption and light harvesting. The device has been realized by the deposition of MoS₂ by pulsed laser deposition on GaN NRs/Si grown via molecular beam epitaxy. The MoS₂/GaN/Si-based 1D–2D conformal PD exhibits a high photoresponse in a broad range of wavelengths (300–1000 nm) in the self-powered mode. The maximum responsivity of the PD is found to be ∼14.22 A W⁻¹ with ultrafast rise and fall times of 38.8 and 8.2 μs, respectively. Our findings demonstrate that conformal PDs based on the MoS₂/GaN NR heterojunction hold promising potential for applications in the field of optoelectronics.