Enhanced light output in roughened GaN-based light-emitting diodes using electrodeless photoelectrochemical etching

We have demonstrated enhanced output power from roughened GaN-based light-emitting diodes (LEDs) by using electrodeless photoelectrochemical etching with a chopped source (ELPEC-CS etching). It was found that the 20-mA output power of the ELPEC-CS treated LED (with roughened surfaces on the top p-type and bottom n-type GaN surface as well as the mesa sidewall) was 1.41 and 2.57 times as high as those LEDs with a roughened p-type GaN surface and a conventional surface, respectively. The light output pattern of the ELPEC-CS treated LED was five times greater than the conventional LED at 0° which was caused by the roughened GaN surface that improved the light extraction efficiency of the LED.