Nitride-based LEDs with p-InGaN capping layer

Nitride-based light-emitting diodes (LEDs) with Mg-doped In/sub 0.23/Ga/sub 0.77/N capping layers were successfully fabricated. Compared to Mg-doped GaN layers, it was found that we could achieve a much larger hole concentration from Mg-doped In/sub 0.23/Ga/sub 0.77/N layers. It was also found that we could reduce the 20 mA operation voltage from 3.78 to 3.37 V by introducing a 5-nm-thick In/sub 0.23/Ga/sub 0.77/N layer on top of the p-GaN layer. Furthermore, it was found that output intensity of LEDs with In/sub 0.23/Ga/sub 0.77/N capping layer was much larger, particularly at elevated temperatures.