Growth and Characterization of Cu2In4Se7 Epitaxial Films

Thin films of Cu₂ln₄Se₇ were grown by molecular beam epitaxy. Vacancy ordering and domain structures in Cu₂In₄Se₇ were characterized by transmission electron microscopy. A photoluminescence (PL) study showed that a major emission peak at 0.943 eV was due to the the In_Cu, → V_Cu emission. Thermal annealing of the film might change the film composition and refine defect structures, which in turn caused a shift of the PL peak and an increase in the peak intensity.