Thermal stability of Si-doped InGaN multiple-quantum wells for high efficiency light emitting diodes

Excitation power dependent photoluminescence (PL) spectroscopy was employed to determine the thermal degradation of InGaN quantum wells (QWs) structure with different Si doping in well region. At a low excitation power density, PL intensity of undoped InGaN well was significantly decreased, while those of interfacial and full Si-doped InGaN well were slightly reduced by rapid thermal annealing (RTA) process. However, PL measurement with high excitation power density showed that PL intensities of InGaN QWs regardless of Si doping were almost similar with/without RTA process. In addition, x-ray diffraction results indicated that Si-doping in well could improve the interfacial quality of InGaN QWs. Therefore, we suggest that Si doping suppress the generation of nonradiative recombination centers by thermal degradation at weaker localization states which could be easily filled by low excitation carriers.