Enhanced light trapping in GaN thin films with Al nanoparticles for photocathode applications

Highlights: • We studied the absorption differences of the GaN thin film with nanoparticles (NPs) in different positions. • We use COMSOL Multiphysics software for simulation calculation. • DepositingAl NPs on the surface of the GaN thin film can obtain higher absorption performance than pure GaN thin film. • Al NPs arrays with a certain radius and period can enhance the light trapping performance effectively. In this paper, the light absorption model of GaN thin film with metal nanoparticle array is constructed based on COMSOL Multiphysics software, and the effect of metal nanoparticles on the light absorption performance of GaN thin film is studied. Compared with Au and Ag, Al nanoparticle array can enhance the absorption of ultraviolet light in GaN thin film, and the structure of Al nanoparticles deposited on the surface of GaN films has high light trapping properties. Therefore, Al nanoparticle array, as a method of improving the ultraviolet absorption performance of GaN, can provide some references for the design of ultraviolet photocathode, which will contribute to the development of high-efficient ultraviolet photocathode.