Direct growth of heteroepitaxial CuInSe2 on GaN (0001) by molecular beam epitaxy

Near stoichiometric chalcopyrite Cu-rich and In-rich CuInSe2 thin films have been simultaneously grown on GaN (0001) by molecular beam epitaxy. Microstructure analysis of the Cu-rich and In-rich CuInSe2 showed that the rotation twin was formed at the interface of CuInSe2/GaN, and no interface reaction occurs between CuInSe2 and GaN. Our experimental results show that GaN is stable for the epitaxial growth of CuInSe2 thin film, which exhibits a promising potential for optoelectronic applications.