Comparison of various surface textured layer in InGaN LEDs for high light extraction efficiency.

The various surface texturing effects of InGaN light emitting diodes (LEDs) have been investigated by comparison of experimented data and simulated data. The single-layer and double-layer texturing were performed with the help of ITO nanospheres using wet etching, where the ITO ohmic contact layer and the p-GaN layer are textured using ITO nanospheres as an etch mask. In case of single-layer texturing, p-type GaN layer texturing was more effective than ITO ohmic contact layer texturing. The maximum enhancement of wall-plug efficiency of double-layered textured LEDs is 40% more than conventional LEDs, after packaging at an injected current of 20 mA. The increase of light scattering at the textured GaN surfaces is a major reason for increasing the light extraction efficiency of LEDs.