Abstract: An (Al,In,Ga)N and ZnO direct wafer bonded light emitting diode (LED), combined with a second light extractor acting as an additional light extraction method. This second light extraction method aims at extracting the light which has not been extracted by the ZnO structure, and more specifically the light which is trapped in the (Al,In,Ga)N layer. This second method is suited for light extraction from thin films, using surface patterning or texturing, or a photonic crystal acting as a diffraction grating. The combination of both the ZnO structure and the second light extraction method enables most of the emitted light from the LED to be extracted. In a more general extension of the present invention, the ZnO structure can be replaced by another material in order to achieve additional light extraction. In another extension, the (Al,In,Ga)N layer can be replaced by structures comprising other materials compositions, in order to achieve additional light extraction.

Abstract: A single or multi-color light emitting diode (LED) with high extraction efficiency is comprised of a substrate, a buffer layer formed on the substrate, one or more patterned layers deposited on top of the buffer layer, and one or more active layers formed on or between the patterned layers, for example by Lateral Epitaxial Overgrowth (LEO), and including one or more light emitting species, such as quantum wells. The patterned layers include a patterned, perforated or pierced mask made of insulating, semiconducting or metallic material, and materials filling holes in the mask. The patterned layer acts as an optical confining layer due to a contrast of a refractive index with the active layer and/or as a buried diffraction grating due to variation of a refractive index between the mask and the material filling the holes in the mask.