ZnS buffer layer for CdS/CdTe based solar cells –A preliminary study

Abstract

Among thin film solar cell materials, cadmium sulphide (CdS) has to been found to be the most suited window material as a heterojunction partner in cadmium telluride (CdTe) based solar cells. By introducing a buffer layer to the heterojunction, the efficiency of the solar cell can be enhanced. The present study focus on identifying optimum conditions for electrodeposition of zinc sulphide (ZnS) buffer layer for CdS/CdTe solar cells. This study revealed that, the electrolytes containing 0.1 mol/L Na2S2O3 and 0.1 mol/L ZnSO4 within the pH range of 4.00-4.50 at 30 ∘C can be used for electrodeposition of ZnS thin films on Florine doped SnO2 (FTO) coated soda lime glasses at potentials between [(-1000) -(-1200)] mV. The developed materials were characterized using UV-visible spectrophotometry and scanning electron microscopy (SEM) techniques. The optical absorption measurement shows a low light absorbance within the range of (3.60-3.70) eV and SEM studies demonstrate the uniform distribution of ZnS grains on the FTO glass substrate.