InGaN/GaN Light-Emitting Diodes with Overcut-Shaped Periodic Microstructures Formed by Wet Etching Process

In this article, overcut-shaped periodic microstructures (OSPMs), embedded InGaN/GaN light-emitting diodes (LEDs), are fabricated using a 2 M aqueous KOH solution wet etching process. Inclined overcut microstructures are formed as the GaN facets and GaN facets with angles of 57 and 62°. This can be attributed to the crystallographic properties of GaN by the difference in etch rates between the Ga face and the N face. The light extraction properties of OSPM-LEDs are effectively extracted upside of the LED device by entirely deflected photons from the inclined overcut microstructures.