Patent ID: 7138666

Claim:
A light-emitting device, comprising: a multi-layer stack of materials including a light-generating region and a layer of n-doped semiconductor material supported by the light-generating region, and a support, and a layer of reflective material that is capable of reflecting at least about 50% of light generated by the light-generating region that impinges on the layer of reflective material, the layer of reflective material being between the support and the multi-layer stack of materials, a current-spreading layer supported by the light-generating region and formed between the layer of n-doped semiconductor material and the light-generating region, wherein: the light-generating region is between the layer of n-doped semiconductor material and the support; a surface of the layer of n-doped semiconductor material is configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the layer of n-doped semiconductor material; the surface has a dielectric function that varies spatially according to a complex periodic pattern; and a distance between a layer of p-doped semiconductor material and the layer of reflective material is less than a distance between the layer of n-doped semiconductor material and the layer of reflective material.