LIGHT EMITTING APPARATUS INCLUDING SUBSTRATE WITH CONVEX-CONCAVE SURFACE OPPOSITE TO SURFACE ON WHICH LIGHT EMITTING ELEMENT IS ARRANGED, AND METHOD FOR FORMING THE SAME

摘要

PURPOSE: A light emitting apparatus and a method for forming the same are provided to achieve improved extraction efficiency and higher luminance in a specific direction. CONSTITUTION: A light emitting apparatus comprises a substrate(1), and a light emitting element(2) arranged on the substrate. The light emitting element has a light emitting layer(21) interposed between a pair of electrodes(20,22). Light generated by the light emitting layer is emitted to the outside of the apparatus through the substrate. The substrate has a first surface on which the light emitting element is arranged, and a second surface opposite to the first surface. The second surface is a convex-concave surface having a plurality of projections. Mean spacing of projections arranged in the vicinity of each other, or mean spacing of peaks of projections arranged in the vicinity of each other is three times larger than and two-hundred times smaller than the longest wavelength of light generated by the light emitting layer. The convex-concave surface has an arithmetic mean slope of 3 to 20 degrees.