Patent ID: 7071617
Filing Date: 2006-07-04
Classification: H01L,Y10T

Abstract:
1. A light-emitting apparatus comprising a substrate and a light-emitting device provided on the substrate, wherein the device includes a light-emitting layer located between a pair of electrodes, a face of the substrate on which the light-emitting device is formed 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, wherein at least one of the following requirements (i)–(vi) is satisfied: (i) the arithmetic mean slope Δa of the uneven surface is in a range between 4° and 30°, inclusive; (ii) the root mean square slope Δq of the uneven surface is in a range between 4° and 35°; (iii) the ratio Ra/Sm of the arithmetic mean roughness Ra of the uneven surface to the mean spacing Sm of asperities is in a range between 0.008 and 0.09, inclusive; (iv) the ratio Ra/S of the arithmetic mean roughness Ra to the mean spacing S of peaks is in a range between 0.009 and 0.10, inclusive; (v) the ratio Rz/Sm of the ten-point height of irregularities Rz of the uneven surface to the mean spacing Sm of asperities is in a range between 0.05 and 0.22, inclusive; and (vi) the ratio Rz/S of the ten-point height of irregularities Rz to the mean spacing S of peaks is in a range between 0.05 and 0.25, inclusive.