GaN-based Light Emitting Diode with Embedded SiO2 Pattern for Enhanced Light Extraction

The n-GaN layer of c-plane GaInN/GaN light emitting diodes (LEDs) on sapphire was modified to contain a pattern of SiO2 nanorods. This embedded pattern of 300 nm long rods and diameter of 200 400 nm was created by thermal agglomeration of a Ni mask layer and subsequent dry-etching. The light output power (LOP) and external quantum efficiency (EQE) of the resulting LEDs increased both by some 25% to 40% depending on current density over the unpatterned structure. The increase is thought to be primarily the result of enhanced light extraction efficiency induced by enhanced scattering at the substrate-side interface.