Light-emitting apparatus and method for forming the same

A method for manufacturing a light-emitting apparatus having a light-emitting layer, comprising:

• preparing a substrate;
• forming an uneven surface having a plurality of asperities on a face of the substrate, wherein 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 the uneven surface is formed such that 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, and
• forming on the uneven surface a light-emitting device having the light-emitting layer and a pair of electrodes between which the light-emitting layer is located such that the light-emitting device is curved along the uneven surface.