Novel processing for improving optical property of InGaN/GaN MQW light-emitting diode

The optical property and microstructure of InGaN/GaN MQW before and after annealed has been investigated by using photoluminescence (PL) and Transmission Electron Microscope (TEM) technique. The photoluminescence intensity of InGaN/GaN MQW LED annealed within AlN powder can be enhanced by 5 times compared with the as-grown one. The diffused Al converted the InGaN/GaN into AlGaN/InGaN. Less dislocation density in the annealed film and more carrier collection ability due to the band gap difference between InGaN/GaN and InGaN/AlGaN can be applied to explain the astonished result. This simple process can improve the optical property of GaN/InGaN QW LED without spending heavy cost in thin film growth.