The effect of transparent conductive nanocrystalline oxide thin layer on performance of UV detectors fabricated on Fe-doped GaN

Two kinds of metal-semiconductor-metal (MSM) Schottky UV detectors with and without an insertion layer of transparent conductive nanocrystalline oxide were fabricated on Fe-doped semi-insulating GaN epilayers. It is found that the optical responsivity of the detectors can be significantly improved by two orders of magnitude by inserting a thin layer of Ga-doped nanocrystalline ZnO (GZO) between metal electrode and Fe-doped GaN. Such improvement is suggested to be associated with the valence-band discontinuities and efficient suppression recombination of traps induced by Fe impurities in GaN due to the insertion of a thin layer of GZO.