High quantum efficiency metal-semiconductor-metal ultraviolet photodetectors fabricated on single-crystal GaN epitaxial layers
The authors report a GaN metal-semiconductor-metal photodetector with high quantum efficiency (~50%) in the absence of internal gain. These photodetectors have a flat responsivity above the bandgap (measured at ~0.15 A/W) with a sharp, solar-blind cutoff at the band edge. There is no discernible responsivity for photons below the bandgap energy. In addition, a very low dark current was obtained, measured at ~800 fA at –10 V reverse bias.
