EFFECT OF HEAT-TREATMENT ON THE STRUCTURAL AND OPTICAL-PROPERTIES OF CULNTE2 THIN-FILMS

The CuInTe2 thin films were prepared by thermal vacuum evaporation of the bulk compound. The structural and optical properties in the temperature range 300-473 K of thin films grown on glass substrates and annealed in vacuum were studied. The films were investigated by X-ray diffraction and electron microscope techniques. The calculated lattice constants for CuInTe2 powder were found to be a=0.619 nm and c=1.234 nm. From the reflection and transmission data, the optical constants, refractive index n, absorption index, k, and the absorption coefficient, alpha, were computed. The optical energy gap was determined for CuInTe2 thin films heat treated at different temperatures for different periods of time. It was found that E(g) increases with both increasing temperature and time of annealing.