The presence of chloride ions in the electrolyte affected the electrodeposition behavior of CdTe from the ammoniacal basic electrolyte of pH 10.7, and changed the properties of the resulting CdTe layers. The photo-assisted effect, that is, the increase in the deposition rate under the irradiation of white visible light onto the growing surface of the CdTe, was depressed in the chloride electrolyte. A set of cyclic voltammograms for basic electrolytes containing only Cd (II) or Te (IV) ions suggested that the chloride ions depress the reduction of not Cd (II) ions, but Te (IV) ions. The deposit prepared from chloride electrolyte was slightly Cd-rich CdTe containing additional phases, such as elemental Cd and Cd3Au. The measurements of the reflectivity spectra and the electrical property suggested that the CdTe electrodeposited from the chloride electrolyte is a complicated compensated semiconductor, because chlorine atoms substituted for Te atoms in CdTe crystals formed some impurity levels in the band gap of CdTe.
