Plasmonic enhancement of photocurrent in GaN based UV photodetectors

Abstract

200 nm thick films of gallium nitride were grown on sapphire substrate using molecular beam epitaxy. Gold nanoparticles were fabricated on the grown films by thermal evaporation followed by annealing. Aluminium nanostructures were fabricated on another set of films using nanosphere lithography. Interdigited electrodes were fabricated using standard lithography to form metal-semiconductor-metal photodetectors. The performance of bare gallium nitride films were compared with the samples that had Au nanoparticles and Al nanostructures. An enhancement of the photocurrent with negligible change in dark current was observed in both cases.