Red emitting LEDs formed by indium rich quantum dots incorporated in MQWs

Abstract

indium rich InGaN nanostructures grown by MOCVD were incorporated in InGaN/GaN quantum wells for long wavelength emission by optimizing the growth condition for the quantum dots (QDs) and InGaN quantum wells. The indium rich InGaN QDs were about 20 nm in diameter and 1.5 nm in height with a density of ∼1 × 10 10 cm -2. The InGaN nanostructures in quantum wells capped by AlN were insensitive to In out-diffusion due to formation of stable Al-N bonds and lower mobility of Al adatoms on the film surface at 780 °C. The piezeoelectric field in the active layers of the light emitting diodes (LEDs) was reduced with the AlN capped layer and minimal blueshift of the electroluminescence was observed as compared to conventional InGaN/GaN LEDs was noted. The energy band profile of strained AlN/InGaN/QDs/InGaN/GaN quantum well system was analyzed. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.