Minority carrier lifetime measurement in GaN by a differential phase technique

In this paper, we discuss the experimental measurement of minority carrier lifetime in gallium nitride (GaN) by a differential phase technique. This technique involves measuring the phase difference between two optical signals and from this measurement, calculating the minority carrier lifetime. Sample structures were designed using commercial, MEDICI, software with in-house developed libraries, to model the band diagrams of the structures required. Initial experimental results have shown that the photoluminescence signals from the GaN can be detected. Electronic noise levels within the system have been reduced by a combination of filtering and averaging. Confirmation of the measurements awaits results from alternative methods.