Improvements in stoichiometry and stability of p-CuxS in thin-film CdS solar cells

To counter the problem of instability, irreproducibility, and low stoichiometry of p-CuxS layers in thin-film CdS solar cells, a new field-assisted chemiplating process of barrier formation is described. Using the dc-forming potential as a first-order variable, nominal deviation from Cu2S composition without any dependence on external process parameters has been obtained. The stability of higher composition CuxS is attributed to the formation of a Cd++, rich barrier layer at the growing CuxS interface towards the CdS side, as inferred from the spectral response and Auger Cu and Cd compositional depth profile of the solar cells.