Nitride-based QD LEDs

InGaN/GaN light-emitting diodes (LEDs) with multiple-quantum-dot (MQD) active layers were fabricated by using an interrupted growth method. We have formed nanoscale QDs embedded in quantum wells (QWs) with a typical 3-nm height and 10-nm lateral dimension. It was found that a large 68.4 meV blue shift in electroluminescence (EL) peak position occurred as the injection current increased from 3 to 50 mA for the MQD LED. The large EL blue shift reveals that deep localization of excitons (or carriers) originates form QDs strengthens the band-filling effect as the injection current increases.