US Patent 7943950 Structured substrate for a LED

A substrate (1) made of a transparent material, preferably glass, which substrate has a planar first side (1a) for the application of an electroluminescent layered structure (21, 22, 23) for emitting light and having a structured second side (1b) for the effective coupling-out of light (6), comprising at least one element of structure (2) comprising first regions (3) having first surfaces (3a) that have a surface roughness of between 0.2 μm and 100 μm, and preferably of between 0.4 μm and 70 μm, and as a particular preference of between 0.7 μm and 40 μm.