LIGHT EMITTING DEVICE COMPRISING LIGHT EXTRACTION LAYER WITH GRADED REFRACTIVE INDEX AND METHOD OF PREPARING THE SAME

摘要

The present invention relates to a light emitting device which has a high transmission light extraction layer which has graded refractive index by changing temperature in E-beam deposition, and a method for preparing the same. Since the light emitting device has a light extraction layer having a graded refractive index, a reflectance due to the reflectance difference between a semiconductor light emitting device and the air is reduced, so the light emitting efficiency can be improved. The light extraction layer can control reflectance in a deposition layer by controlling temperature in E-beam deposition, thereby changing the composition of existing multicomponent and simplifying a method for forming a refractive index gradient. The refractive index of the light extraction layer continuously changes in a layer made of a single element, thereby effectively performing light extraction without a rapid change in the refractive index.