GaN-based LEDs with Ar plasma treatment

The authors propose a simple Ar plasma treatment method to selectively damage the area underneath p-pad electrode of GaN-based light-emitting diodes (LEDs). It was found that we could form a highly resistive area so that the injected carriers will be forced to spread out horizontally for the LED. Under 20 mA current injection, it was found that the output powers were 16.0, 17.9 and 17.3 mW while the forward voltages were 3.17, 3.19 and 3.20 V for conventional LED and LED with SiO2 layer, respectively. Moreover, the LED with Ar plasma treatment is superior to the other LEDs while operating at a higher injection current.