Study of photocurrent properties of GaN ultraviolet photoconductor grown on 6H-SiC substrate

The properties of a photoconductive ultraviolet detector based on a GaN epi layer grown on a 6H-SiC substrate using metal-organic chemical Vapor deposi tion were investigated. We obtained the detectable energy span of the devic e up to the ultraviolet region by photocurrent measurement. The spectral re sponsivity remained nearly constant for wavelengths ranging from 250 to 365 nm and dropped by three orders of magnitude within 15 nm of the band edge from 365 nm to 380 nm. The detector was measured to have a responsivity of 133 A/W at a wavelength of 360 nm under a 5 V bias, and the voltage-depende nt responsivity was evatuated. Furthermore, a convenient method to determin e the response time was developed. The relationship between response time a nd bias was obtained.