Changes of the structural and optical properties of cubic CdS films on annealing in H2 and air atmospheres
Structural and optical properties of as-grown cubic CdS polycrystalline films annealed in H2 and air atmospheres are reported. The CdS films were grown onto glass substrates by chemical-bath deposition. The forbidden band-gap and the x-ray diffraction spectrum evolution as a function of the thermal annealing temperature, in H2 and air ambients, were studied. Band-gap shift and changes in grain size, lattice parameter and crystalline structure were influenced by the type of atmosphere and the temperature of the thermal annealing. From these results, the dependence of the band-gap on the lattice parameter was determined.