Screen printed CdS Te1- films, structural and optical characterization

We present a study of the electronic and structural properties of screen printed CdS x Te 1-x films. Nominal CdS x Te 1-x alloys were prepared in the whole compositional range by mixing CdS and CdTe powders plus CdCl 2 as a flux. The mixtures were screen printed and then sintered at 515°C under a nitrogen flux. The employed characterization techniques were X-ray diffraction (XRD), optical transmission (OT) and photoluminescence (PL). From PL measurements, we concluded that single phase samples were obtained in the ranges 0 ≤ x ≤ 0.12 and 0.97 ≤ x ≤ 1 for the temperature employed. We present the behavior of lattice parameters and energy band gap, as a function of sulphur content, obtained from the analysis of XRD patterns and OT spectra. In a consistent way, all the results indicate the presence of just two phases within the miscibility gap, one CdTe-like and the other CdS-like. This could be employed to solve the interdiffusion problem in CdS/CdTe solar cells.