The effect of the transparent conductive oxide on the performance of thin film CdS/CdTe solar cells

Thin film CdS/CdTe solar cells fabricated on SnO_x -coated glass have been found to give higher efficiencies than similar cells produced on indium-tin oxide (ITO) coated glass substrates. Further investigation implicated the CdS/ITO interface as the cause of the problem; current-voltage measurements revealed that on heating in air the CdS/ITO junction became rectifying. This is consistent with recently reported findings which show that the work function of ITO is raised above that of CdS by oxidative treatments (such as heating in air) which would make the ITO/CdS junction rectifying rather than ohmic.