Dual-band photodetector with a hybrid Au-nanoparticles/β-Ga2O3 structure

Abstract

Hybrid Au-nanoparticles (NPs)/β-Ga₂O₃ thin films were fabricated by laser molecular beam epitaxy of high quality β-Ga₂O₃ thin films on c-plane sapphire substrates followed by spin coating and post annealing of Au NPs. Photodetectors (PDs) made of hybrid Au-NPs/β-Ga₂O₃ thin films and bare β-Ga₂O₃ thin films are comparatively studied. It is found that Au-NPs can obviously improve the performances of PDs. Lower dark current, higher photoresponse and faster switching time under 254 nm light illumination are obtained by introducing Au-NPs. The localized surface plasmonic resonance from Au-NPs could be attributed to the enhanced performance. Meanwhile, a photoelectric response to 532 nm light illumination is observed in an Au NPs/β-Ga₂O₃ based PD. It is suggested that our hybrid Au-NPs/β-Ga₂O₃ PD could serve as a dual-band detector in one device.