GaN-based light-emitting diode with textured indium tin oxide transparent layer coated with Al2 O3 powder

Surface-textured InGaN/GaN light-emitting diodes (LEDs) coated with transparent Al2 O3 powder were fabricated by natural lithography combined with inductively coupled plasma etching. For surface texturing, 300 nm size Al2 O3 powder is used as an etching mask by simply coating the surface using a spin-coating process. Also, the powders are left on the surface after surface texturing to further increase extraction efficiency. At 20 mA, the light output power of the textured indium tin oxide (ITO) InGaN/GaN LEDs coated with the Al2 O3 powder is enhanced by ∼112% compared with the conventional nontextured ITO LED. The enhanced light output power is attributed to the improved extraction efficiency resulting from an overall decrease in the total internal reflection due to the textured surface and the Al2 O3 powder coating.