Semiconductor light emitting device and method
AssigneeLumileds Lighting U.S., LLC
InventorsDaniel A. Steigerwald, Michael R. Krames
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Abstract
A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient α, at the emission wavelength of the active region, of α>3 cm−1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, α, of the substrate material is α<1 cm−1.
Claims30
A light-emitting device, comprising:
- a semiconductor structure formed on one side of a substrate, said semiconductor structure having a plurality of semiconductor layers and an active region within said layers;
- and
- first and second conductive electrodes contacting respectively different semiconductor layers of said structure on said one side of said substrate;
- said substrate comprising a material having a refractive index n>2.0 and light absorption coefficient α, at the emission wavelength of said active region, of α<3 cm−1.
A light emitting device, comprising:
- a semiconductor structure formed on one side of a substrate, said structure having a plurality of semiconductor layers and an active region within said layers, said plurality of layers including an n-type layer of a III-nitride semiconductor and a p-type layer of III-nitride semiconductor on opposing sides of said active region;
- first and second conductive electrodes respectively contacting said n-type layer and said p-type layer;
- and
- means for applying electric signals across said electrodes to produce light at said active region, the majority of said light being emitted from said device via said substrate;
- said substrate comprising a material having a refractive index n>2.0 and light absorption coefficient α, at the emission wavelength of said active region, of α<3 cm−1.
A light emitting device, comprising:
- a semiconductor structure formed on one side of a substrate, said structure having a plurality of semiconductor layers and an active region within said layers, said plurality of layers including an n-type layer of a III-nitride semiconductor and a p-type layer of III-nitride semiconductor on opposing sides of said active region;
- first and second conductive electrodes respectively contacting said n-type layer and said p-type layer;
- and
- means for applying electric signals across said electrodes to produce light at said active region, the majority of said light being emitted from said device via said substrate;
- said substrate comprising polycrystalline silicon carbide.
Dependencies are inferred from the claim text.