Light-output enhancement in a nitride-based light-emitting diode with 22° undercut sidewalls

We successfully fabricated nitride-based light-emitting diodes (LEDs) with ∼22° undercut sidewalls. The ∼22° etching undercut sidewalls were achieved by controllable inductively coupled plasma reactive ion etching. With a 20-mA current injection, the output powers of the LED with ∼22° undercut sidewalls and standard LED were 5.1 and 3 mW, respectively - a factor of 1.7 times enhancement. It was found that such undercut sidewalls could enhance the probability of escaping the photons outside from the LED in the near horizontal and in-plane directions. This simple and controllable method is beneficial to fabricate brighter LEDs.