Pulsed excimer laser ablated copper indium diselenide thin films

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.