Light-output enhancement of GaN-based light-emitting diodes by using hole-patterned transparent indium tin oxide electrodes

We have demonstrated the improvement of the light-output power of GaN-based light-emitting diodes (LEDs) using hole-patterned indium tin oxide (ITO) p -type electrodes. Hole patterns were defined by a laser holographic lithography combined with a postlithography deposition process. It is shown that near-UV LEDs made with the patterned ITO with a hole period of 710 nm and a size of 320 nm give 23% and 67% higher light-output power (at 20 mA) than those of LEDs with unpatterned ITO and NiAu contacts, respectively. It is further shown that the reduction of the hole period results in an additional improvement of light-output power.