The Luminescence Properties of Eight Periods In0.2Ga0.8N/GaN Multiple Quantum Wells with Silicon Doping in the First Two to Five Barriers of Blue LEDs

We have been carrying out researches on luminescence properties of first two to five barriers in the growth sequence with silicon (Si) doping of eight periods In0.2Ga0.8N/GaN quantum wells (QWs) and we have published papers in Journal of Luminescence, Vol. 177, pp. 59–64, 2016. This paper provides more information on their properties. Epilayers are grown by low pressure metal-organic chemical vapor deposition (LPMOCVD) system on patterned sapphire substrates (PSSs). For the sample’s QWs containing first four barriers with Si doping, photoluminescence (PL) demonstrates the strongest intensity and relative larger spectral linewidth than other samples. It is originated from the increase of radiative recombination centers due to the effective reduction of quantum confined Stark effects (QCSE) and enhancements of carrier localization inside QWs. Higher output power and external quantum efficiency (EQE) are also shown in this blue LED. Soft confinement among QWs leads to reduction of Auger processes, leakage of carriers out of QWs, and nonradiative recombination centers in this sample. First four barriers with Si doping is the favorable doping condition for eight periods In0.2Ga0.8N/GaN QWs.