Fabrication of non-polar GaN based highly responsive and fast UV photodetector

We report the fabrication of ultraviolet photodetector on non-polar (11-20), nearly stress free, Gallium Nitride (GaN) film epitaxially grown on r-plane (1-102) sapphire substrate. High crystalline film leads to the formation of two faceted triangular islands like structures on the surface. The fabricated GaN ultraviolet photodetector exhibited a high responsivity of 340 mA/W at 5V bias at room temperature which is the best performance reported for a-GaN/r-sapphire films. A detectivity of 1.24 x 10(9) Jones and noise equivalent power of 2.4 x 10(-11) WHz(-1/2) were also attained. The rise time and decay time of 280 ms and 450 ms have been calculated, respectively, which were the fastest response times reported for non-polar GaN ultraviolet photodetector. Such high performance devices substantiate that non-polar GaN can serve as an excellent photoconductive material for ultraviolet photodetector based applications.