Photoconductive GaN ultraviolet detector

The photocurrent properties of the conductive GaN ultraviolet detector grown on 6H-SiC substrate by metallorganic chemical vapor deposition are investigated. The detectable energy span of the detector up to ultraviolet is obtained by photocurrent measurement. The spectral responsivity remains nearly constant for wavelength from 250nm to 360nm, and a long-wavelength cut-off at 365nm (approx. 3.4eV) is observed. The detector responsivity is measured as 133A/W at a wavelength of 360nm under a 5-V bias, and the voltage-dependent responsivity is performed. Based on the relationship between the intensity of photocurrent and modulation frequency, the response time of the detector is determined by fitting the experimental data.