Effects of Rough P-GaN Layer on Improving Light Extraction Efficiency of 630-nm AlGaInP LEDs

The effects of using a rough p-GaN layer to improve the light extraction efficiency of a 630-nm AlGaInP light-emitting diode (LED) are investigated. It is found that the light extraction efficiency significantly depends on the surface morphology of the rough p-GaN layer grown on the top GaP layer of AlGaInP LED at 525^°C using metal organic chemical vapor deposition. The highest output power of 5 mW is observed from the 630-nm AlGaInP LED chip with a rough p-GaN layer fabricated at the Mg flow rate of 400 sccm, which shows a relative increase of 115% as compared with conventional one.