Temperature-dependent time-resolved photoluminescence measurements of (1-101)-oriented semi-polar AlGaN/GaN MQWs

We studied the temperature dependence and the recombination dynamics of the photoluminescence of (1-101)-oriented semi-polar Al 0.2 Ga 0.8 N/GaN multiple quantum wells (MQW). The polarized low-temperature PL measurements reveal that radiative recombination exhibit an anisotropic behavior. The PL intensity at room temperature is reduced by one order of magnitude with respect to low temperature. The radiative decay time exhibits a mixed behavior: it is roughly constant between 8K to ranging near 140-150K and then rapidly increases with a slope of 10 ps.K -1 . This behavior is indicative of coexistence of localized excitons and free excitons which relative proportion are statistically computed.