Output power enhancement of InGaN/GaN based green light-emitting diodes with high-density ultra-small In-rich quantum dots

Abstract

InGaN/GaN-based green light-emitting diodes (LEDs) with high-density ultra-small In-rich quantum dots (QDs) embedded in InGaN multiple quantum wells via spinodal decomposition are grown by metal organic chemical vapor deposition. The density and average size of In-rich QDs increased from 1×1011cm−2 to 2×1012cm−2 and decreased from 8.4nm to 2.3nm, respectively, when the NH3 flow rate was reduced during the growth of InGaN active layers. The associated growth mechanism of QDs is discussed. High-density ultra-small QDs with improved internal quantum efficiency due to good carrier confinement and a small number of defects are obtained. The proposed approach improves the light emission efficiency of InGaN QD-based LEDs and a 10% enhancement in light output power for packaged lamp-form LEDs is demonstrated in this work.