The effect of SnO2 roughness on the properties of CdTe/CdS solar cells

Tin oxide is the most commonly used transparent conducting oxide for CdTe solar cells. Its properties are critical to solar cell performance, in particular when CdS films of small thicknesses are utilized. Using thin CdS films to enhance the photocurrent of CdTe solar cells typically leads to lower V_ocs and fill factors. This is believed to be due to the presence of pinholes in CdS which lead to the direct contact of the CdTe layer with SnO₂. The main objective of this work is to study the effect of the roughness/grain size of the SnO₂ films on the performance of CdTe solar cells. It has been found that as the roughness/grain size of the SnO₂ increases, the performance of CdTe cells fabricated using thin CdS films improves