Enhance the luminance intensity of InGaN-GaN light-emitting diode by roughening both the p-GaN surface and the undoped-GaN surface using wafer bonding methods

An InGaN-GaN light emitting diode (LED) with double roughened surfaces was fabricated by surface-roughening, wafer-bonding and laser lift-off technologies. It was found that the frontside luminance intensity of double roughened LED was 2.77 times higher than that of the conventional LED at an injection current of 20 mA. The backside luminance intensity was 2.37 times higher than that of the conventional LED. This is because the double roughened surfaces can provide photons multiple chances to escape from the LED surface, and redirect photons, which were originally emitted out of the escape cone, back into the escape cone. copyright The Electrochemical Society.