Enhanced light output power of GaN-based light emitting diodes with overcut sideholes formed by wet etching

Light emitting diodes (LEDs) have been fabricated, with an overcut sidehole (OS) structure in the LED mesa. The OSs with ∼57° angle has been perfectly formed by wet-etching with a simple and controllable process. Lateral light that is guided along the GaN epilayer in the OS–LEDs is found to be significantly redirected by the OS structure as a reflector, and can be extracted from the LEDs. The performance of the OS–LEDs is compared with that of conventional LEDs and the light output power of the OS–LED is enhanced by 49% over that obtained from conventional LEDs. It is noticed that wet etching does not degrade the electrical properties of the devices.