THIN FILMS OF CADMIUM TELLURIDE PRODUCED USING STACKED ELEMENTAL LAYER (SEL) PROCESSING FOR USE IN THIN FILM SOLAR CELLS

The stacked elemental layer (SEL) technique has been used to synthesise thin films of CdTe. This technique consists of depositing alternate layers of Cd/Te in the stoichiometric ratio and then annealing the stack to react the layers to form the compound. The Cd and Te layers were deposited using thermal evaporation and annealed in nitrogen, vacuum or air. Transmittance and reflectance data, X-ray diffraction data and scanning electron microscopy observations of the surface topology are given for the layers produced. Post synthesis annealing of the layers using CuCl2/CdCl2/methanol was also investigated. This was found to substantially increase the grain size of the layers produced. This process promises to be a low cost method for producing large areas suitable for use in solar cell structures. A preliminary energy analysis has been carried out and energy payback times and energy ratios are presented.