Optical Quenching of Photoconductivity in GaN Photo-conductors

We report the first observation of optical quenching of photoconductivity in GaN photoconductors at room temperature. Three prominent quenching bands were found at Ev+1.44, 1.58 and 2.20 eV, respectively. These levels are related to the three hole traps in GaN materials based on a hole trap model to interpret the quenching mechanism. The responsivity was reduced about 12% with an additional He-Ne laser shining on the detector.