Impact of GaN buffer layer on the growth and properties of InN islands

Uncapped InN islands are grown on GaN buffer layers by low pressure metal-organic chemical vapor deposition. The buffer layer threading dislocation density is intentionally altered via the GaN growth pressure, as indicated by both the x-ray diffraction and atomic force microscopy. InN island density and size vary markedly depending on the threading dislocation density in the buffer layers. Islands grown on the buffer layers with reduced threading dislocation densities exhibit narrow x-ray diffraction peaks and strong room temperature photoluminescence.