Light-emitting apparatus and method for forming the same

摘要

In a bottom emission type light-emitting apparatus, a face of a substrate, which is opposite from a light-emitting device, is an uneven surface having a plurality of asperities. The mean spacing Sm of adjacent asperities or the mean spacing S of peaks of adjacent projections of the asperities is no less than three times the longest wavelength of light generated by the light-emitting layer and no more than two hundred times the longest wavelength. The arithmetic mean slope Aa of the uneven surface is in a range between 3° and 20°, inclusive. Therefore, the apparatus substantially has higher extraction efficiency and a higher brightness in a specific direction.