The impact of plasmonic Ag-Au bimetallic nanoparticles on photocurrent enhancement in GaN-based photodetectors

Abstract

Recently, there has been considerable interest in high-efficiency ultraviolet (UV) photodetectors for their potential practical uses. In this study, a high-quality UV photodetector was fabricated using a combination of Ag and Au NPs with GaN film. The GaN film was deposited using sputtering technique, whereas Ag and Au films were grown using thermal evaporation technique. Ag-Au bimetallic nanoparticles were formed by treating them at the various annealing temperature to improve the interaction between light and the photoactive layers of the photodetectors. The optimal annealing temperature to achieve the best performance of a photodetector is 650 degrees C. This led to a photoresponsivity of 98.5 A/W and the ON/OFF ratio of 705 at low bias voltage of 1 V. This work establishes the foundation for the advancement of high-performance UV photodetectors.