Temperature and current dependences of electroluminescence from InGaN/GaN multiple quantum wells

Temperature and injection current dependences of the electroluminescence (EL) peak energy and linewidth are studied to investigate the carriers transferring mechanism in InGaN/GaN multiple quantum wells. The S- and W-shaped temperature dependences of the peak energy and linewidth from the EL spectra are demonstrated to be in fair agreement with the carrier motion and thermalization process through hopping over localized states within the In-rich regions. With increasing injection current levels, the S- and W-shaped dependences gradually disappear. The band-filling effect and the heating effect are taken into account to investigate this phenomenon. Moreover, the variations of EL external quantum efficiency as a function of temperature at various injection currents are also obtained. It is observed that the EL efficiency is strongly dependent on working temperature and injection current.