Pulsed excimer laser ablated copper indium diselenide thin films

Abstract

CuInSe₂ thin films of thickness in the range of 0.45-1.8 µm were deposited on glass, Pt coated Si and Mo substrates by pulsed laser ablation at 150° C. Rapid thermal annealing (RTA) at a high heating rate was employed and its effect on crystallinity of the films was investigated. X-ray diffraction patterns of the RTA films, exhibited a highly preferred orientation along the (112) plane establishing the chalcopyrite structure. The composition of the as-grown and RTA films maintained the required stoichiometry ratios uniformly over a reasonable area. The EDAX composition analysis revealed that the films annealed at 500° C for 20 s were slightly indium rich, which consequently led the films to exhibit an n-type conductivity. However, RTA processing of the as-grown films at a higher temperature under controlled soaking time transformed the films to exhibit a p-type conductivity.