InN Layers Grown by MOCVD on a-Plane Al2O3

The conditions for obtaining epitaxial InN layers on a-plane (11-20) sapphire with a GaN buffer layer by MOCVD method are determined for the first time. Comparative studies show that InN layers on a-plane sapphire have higher structural perfection and improved photoluminescence properties compared to those grown on c-plane sapphire. Formation of indium clusters in the InN layers along with the conditions impeding their appearance is considered.