Tunable thermal quenching of photoluminescence in GaN

In this work, we report the observation of abrupt and tunable thermal quenching of photoluminescence (PL) in high-resistivity, undoped GaN. The ultraviolet luminescence (UVL) band in these samples exhibited abrupt and tunable quenching, which is similar to behavior observed for p -type GaN:Mg samples. Such behavior has never been observed for undoped GaN and was very rarely reported for other semiconductors. We describe the effect of temperature and excitation intensity on PL in undoped GaN with a phenomenological model involving three defect species. 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.