${\rm Ga}_{2}{\rm O}_{3}$ /GaN-Based Metal-Semiconductor-Metal Photodetectors Covered With Au Nanoparticles

GaN-based metal-semiconductor-metal photodetectors (PDs) with a β-Ga₂O₃ layer were fabricated. To increase performance, the Ga₂O₃/GaN-based PDs were covered with Au nanoparticles. The reverse leakage current decreased by more than two orders of magnitude with a 10-V applied bias and a 95-fold increase of the rejection ratio (250/360 nm) was achieved with a 1-V applied bias after the PDs were covered with Au nanoparticles. There was an obvious response at 490 nm because of the surface plasmon resonance in Au nanoparticles. The results indicate that Au nanoparticles can be used to improve the performance of optoelectronic devices.