PHOTOCURRENT STUDIES OF ULTRAVIOLET DETECTOR BASED ON GALLIUM NITRIDEEPILAYER

The properties of photoconductive blue and ultraviolet detector based on single crystal GaN epilayer grown on sapphire substrate by metalorg anic chemical vapor deposition were investigated. The observed optical absorption edge of 3.39 eV in optical transmission has been confirmed by the peak of 3.400 eV in photoreflectance. The detectable energy sp an of the GaN device up to ultraviolet was obtained by photocurrent me asurement. The dependence of the intensity of photocurrent on the chop per frequency in the measurement was studied, and an easy method was u sed to determine the response time as 0.4 s.