CADMIUM CHALCOGENIDE SEMICONDUCTING THIN-FILMS PREPARED BY ELECTRODEPOSITION FROM BOILING AQUEOUS-ELECTROLYTES

Thin n-type semiconductive films of CdTe, CdSe and their mixed compoun ds CdSexTe1-x, suitable for solar energy conversion, were prepared by cathodic electrodeposition from an aqueous electrolyte onto titanium e lectrodes. An electrochemical cell was specially designed to perform e lectrodeposition in a boiling bath. The composition of the layers, the ir crystal structure, morphology and band-gap width were studied as fu nctions of the electrochemical parameters and bath concentration. It i s shown that the use of a high temperature improves the crystal qualit y of cadmium chalcogenide thin films even with solutions rather concen trated in selenous acid. CdSe or Se-rich CdSexTe1-x, layers tend in ma ny cases to crystallize in the hexagonal (wurtzite) structure.