Influence of the quantum-confined Stark effect on the temperature-induced photoluminescence blueshift of InGaN/GaN quantum wells in laser diode structures

Measurements of the excitation power-dependence and temperature-dependence photoluminescence (PL) are performed to investigate the emission mechanisms of InGaN/GaN quantum wells (QWs) in laser diode structures. The PL spectral peak is blueshifted with increasing temperature over a certain temperature range. It is found that the blueshift range was larger when the PL excitation power is smaller. This particular behavior indicates that carriers are thermally activated from localized states and partially screen the piezoelectric field present in the QWs. The small blueshift range corresponds to a weak quantum-confined Stark effect (QCSE) and a relatively high internal quantum efficiency (IQE) of the QWs.National Natural Science Foundation of China [61334005, 51272008, 51102003]; National Basic Research Program of China [2012CB619304]SCI(E)EI中国科技核心期刊(ISTIC)ARTICLEhuxd@pku.edu.cn61