III-Nitride light-emitting devices with improved high-current efficiency

A light-emitting semiconductor device (20) comprises a III-Nitride active region (28) and a III-Nitride layer formed proximate to the active region and having a thickness that exceeds a critical thickness for relaxation of strain in the III-Nitride layer. The III-Nitride layer may be a carrier confinement layer (30), for example. In another aspect of the invention, a light-emitting semiconductor device comprises a III-Nitride light emitting layer, an InxAlyGa1-x-yN (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, x + y ≤ 1), and a spacer layer interposing the light emitting layer and the InxAlyGa1-x-yN layer. The spacer layer may advantageously space the InxAlyGa1-x-yN layer and any contaminants therein apart from the light emitting layer. The composition of the III-Nitride layer may be advantageously selected to determine a strength of an electric field in the III-Nitride layer and thereby increase the efficiency with which the device emits light.