Preparation of ZnGa2O4-based deep ultraviolet photodetector with high photodetectivity by magnetron sputtering

Abstract

Ultra-wide bandgap semiconductors are frequently utilized materials in the fabrication of deep ultraviolet photodetectors (DUVPDs). However, it is imperative to enhance both the photoresponsivity and response speed of these detectors. Herein, we deposited high-quality (111)-oriented ZnGa2O4 films with a bandgap of approximately 4.75 eV onto c-plane sapphire (0001) substrates using magnetron sputtering. Our findings illuminate the pivotal role of pressure in shaping their structural properties, chemical compositions, and photoelectric characteristics. Importantly, DUVPDs based on ZnGa2O4 films exhibited a photo/dark current ratio of 1.46 × 104. Furthermore, we observed the highest responsivity to be 72.2 A/W, complemented by a photodetectivity of 4.21 × 1014 Jones, an external quantum efficiency of 4.04 × 104 %, and rise and decay times of 2.32 s and 0.055 s, respectively. This study underscores the commendable photoresponsivity and rapid response time of the ZnGa2O4 photodetector, positioning it as a compelling candidate for the advancement of deep ultraviolet devices.