Dual-wavelength photodetector based on monolayer MoS2/GaN heterostructure

Gallium nitride (GaN) has been confined to ultraviolet (UV) detectors due to its semiconductor characteristic with bandgap of 3.4 eV. In this work, we epitaxially grow two-dimensional (2D) molybdenum disulfide (MoS2) on top of three-dimensional (3D) p-GaN (0001) substrate by confined-space chemical vapor deposition (CVD) method. The optical microscopic and spectroscopic analyses of as-grown triangular monolayer (ML) MoS2 are presented. The fabricated photodetector based on 2D MoS2/3D p-GaN hybrid heterostructure exhibit excellent rectify behavior and dual-wavelength photoresponse, which are measured by current–voltage (I–V) characteristics under dark condition and illumination. In addition, the density functional theory (DFT) calculated results demonstrate the formation of type II band arrangement and enhanced optical properties of the 2D/3D hybrid heterostructure. This work illustrates that the hybrid heterostructure prepared by epitaxially grown 2D materials provides feasible methods for the promising dual-wavelength photodetectors of group III-Nitrides.