Development of back contacts for CdTe thin film solar cells deposited on flexible foil substrates

Abstract

The formation of low resistance ohmic contacts on p-type CdTe is a major challenge for the superstrate solar cell the dominant device configuration for this technology. It is even a greater challenge for the substrate configuration, since the back contact material is deposited first and is therefore influenced by subsequent high temperature fabrication processing. In this paper, the structural and electrical properties of ZnTe and Sb₂Te₃ films deposited by the close-spaced sublimation and evaporation respectively are presented. Thin film CdTe solar cells of the substrate configuration have been fabricated on flexible foil substrates using ZnTe and Sb₂Te₃ as back contacts, and their performance has been evaluated.