III-nitride light emitting device with double heterostructure light emitting region

1. A semiconductor light emitting device comprising:

an n-type region;

a p-type region; and

a light emitting region disposed between the n-type region and the p-type region in a double-heterostructure that includes only a single III-nitride light emitting layer, this light emitting layer being the only layer in the device from which light is produced when current flows between the n-type and p-type region, wherein:

the light emitting layer has a thickness between 100 Å and 600 Å;

the light emitting layer is devoid of any barrier layer;

at least a portion of the light emitting layer has a graded InN composition; and

a plot of InN composition as a function of distance from the n-type region for the light emitting layer comprises a plurality of local minima in InN composition.

2. The semiconductor light emitting device of claim 1 wherein the plot of InN composition as a function of distance from the n-type region for the light emitting layer includes a local maximum in InN composition in a portion of the light emitting layer closest to the n-type region.

3. The semiconductor light emitting device of claim 1 wherein the plot of InN composition as a function of distance from the n-type region for the light emitting layer includes a local maximum in InN composition disposed between two local minima in InN composition.

4. The semiconductor light emitting device of claim 3 wherein the InN composition between the local maximum and one of the two local minima is linearly graded.

5. The semiconductor light emitting device of claim 1 wherein each local minima in the plot of InN composition corresponds to a portion of the light emitting layer with a constant InN composition.

6. The semiconductor light emitting device of claim 1 wherein regions between local maxima in the plot of InN composition do not correspond to quantum wells of the light emitting layer.