Semiconductor light emitting devices with graded composition light emitting layers

摘要

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 In x Ga 1-x N, Al x Ga 1-x N, or In x Al y Ga 1-x-y N.