Semiconductor light emitting devices with graded composition light emitting layers
AssigneePhilips Lumileds Lighting Company, LLC
InventorsYu-Chen Shen, Michael R. Krames, Nathan F. Gardner
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Abstract
A III-nitride light emitting layer in a semiconductor light emitting device has a graded composition. The composition of the light emitting layer may be graded such that the change in the composition of a first element is at least 0.2% per angstrom of light emitting layer. Grading in the light emitting layer may reduce problems associated with polarization fields in the light emitting layer. The light emitting layer may be, for example InxGa1−xN, AlxGa1−xN, or InxAlyGa1−x−yN.
Claims20
A semiconductor light emitting device comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region, the light emitting layer having a graded composition of a first element, wherein a change in composition of the first element in the light emitting layer is greater than 0.2% per angstrom and less than 0.8% per angstrom across a thickness of the light emitting layer.
A semiconductor light emitting device comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region, the light emitting layer having a graded composition of a first element, wherein a change in composition of the first element in the light emitting layer is greater than 0.2% per angstrom and less than 1% per angstrom across a thickness of the light emitting layer, wherein the light emitting layer has a thickness between 100 angstroms and 500 angstroms.
A semiconductor light emitting device comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region, the light emitting layer having a graded composition of a first element, wherein a change in composition of the first element in the light emitting layer is greater than 0.2% per angstrom and less than 1% per angstrom across a thickness of the light emitting layer, wherein the light emitting layer is a first portion of a III-nitride light emitting region, the light emitting region further comprising a second portion of uniform composition.
Dependencies are inferred from the claim text.