Photoreflectance study of Au-schottky contacts on n-GaN

Semi-transparent Au-Schottky contacts on n-GaN were fabricated and studied by room-temperature photoreflectance spectroscopy. A significant difference was observed in the photoreflectance spectra before and after the evaporation of Au-Schottky contacts. This can be interpreted due to the formation of Schottky barrier at the interface between Au and GaN. Furthermore, for the higher doping sample, Franz-Keldysh oscillations were observed in the photoreflectance, which allowed the accurate determination of Au-Schottky barrier height on GaN.