LIGHT EMITTING DEVICE HAVING IMPROVED REFLECTION EFFICIENCY WITH GRADED REFRACTIVE INDEX AND METHOD OF PREPARING THE SAME

摘要

The present invention relates to a light emitting device having improved reflection efficiency by forming a low reflective index layer, which has gradually decreasing reflective index and is formed between a semiconductor material layer and a reflection layer, and to a method of preparing the same. Because the light emitting device has the low reflective index layer which has gradually decreasing reflective index, the light emitting device can guide light with no light loss to a reflection electrode and can obtain an excellent light extraction effect. The low reflection layer controls temperature in E-beam deposition and controls a reflective index in a deposition layer, thereby simplifying a method for forming a reflective index gradient. The lower reflective index layer has a reflective index which continuously changes in a layer made of a single element, thereby improving a light extraction effect without a rapid change in the reflective index.