Fabrication and optical properties of blue LEDs with silica microsphere coating

Abstract

We report the enhancement of light extraction efficiency of InGaN-based blue light emitting diodes by using a surface light-scattering layer. A number of SiO 2 microspheres embedded into a ZrO 2 thin layer played a role of a light-scattering medium. Coating the light-scattering layer on device surface, the interference fringes of electroluminescence (EL) spectra were eliminated and the EL intensity around 440 -450 nm was increased by a factor of 1.3.