DEPENDENCE OF CDS CDTE THIN-FILM SOLAR-CELL CHARACTERISTICS ON THE PROCESSING CONDITIONS/

The effects of post deposition heat treatment on the electrical and st ructural properties of thin film glass/ITO/CdS/CdTe/Au solar cells hav e been investigated. The results of three types of cells: as-deposited , annealed in air at 400 degrees C for 30 min and CdCl2 treated cells are compared. XRD studies of the CdTe layer showed some preferred orie ntation along the {311} direction in as-deposited material, but heat a nd CdCl2 treatments resulted in increased randomisation. Temperature d ependent J-V characteristics indicated that in the as-deposited and he at treated specimens current transport was dominated by tunnelling rec ombination processes. In contrast, in the CdCl2 treated cells, which s howed much improved electrical characteristics, current transport was limited by thermal emission across the junction suggesting a reduction in the interfacial recombination rates. Spectral response measurement s under reverse bias confirmed the improvement in junction characteris tics following CdCl2 treatment.