Analysis of Cd1−xZnxS window effect on CdTe solar cells

In conventional Cadmium telluride (CdTe) solar cells cadmium sulfide (CdS) layer is used as emitter window, the choice proved to be appropriate because of its large energy band gap 2.42 eV and its lattice parameter fits well with CdTe. The inconvenience of this window is its important absorption coefficient in the bleu region. To surmount this problem one of the suggested solutions is to use a much wider energy band gap window layer with suitable parameters onto the CdS layer, or replace the CdS layer with a suitable window. In the present work we investigate the effect of Cd_1-xZn_xS ternary compound window on the top of the p-CdTe cell. The calculations and the analysis are carried out using SCAPS 1D numerical simulator. In this study we deal with two configurations the first structure comprises a double window (Cd_1-xZn_xS /CdS) and the second incorporates a simple (Cd_1-xZn_xS) window. When x is reduced from 0.08 to 0.05 in the second structure, the energy conversion efficiency increases from 17.11 to 21.15 %. While the best obtained energy conversion efficiency of the first structure is about 16.04 % only.