Cu-Ga-Se films of different composition prepared by MBE technique were examined by reflection high energy electron diffraction, electron probe for micro analysis, X-ray diffraction and photoluminescence. The valence stoichiometry of the films is fulfilled at unity molecularity, showing that CuGaSe2 is possible to be grown by MBE. The valence stoichiometry is almost conserved in a wide range of molecularity of the films. It is proven that the films have chalcopyrite structure over a remarkably wide range of Cu-rich composition and that the CuGaSe2 films are epitaxially grown with the c-axis perpendicular to the (001) plane of GaAs substrate. The low temperature photoluminescence on epitaxially grown films of nearly stoichiometric and Cu-rich composition show sharp emission peaks at 1.71 eV attributed to exciton recombination, indicating that the film quality is rather high.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering