ELECTROCHEMICAL DEPOSITION OF PBSE THIN-FILMS FROM AQUEOUS-SOLUTIONS

Electrode processes taking place under cathode polarization in an elec trolyte bath containing Pb(II), Se(TV), acetic acid and EDTA were inve stigated. It was shown that the I-V curve has three characteristic reg ions: (i) catalytic reduction of Se(IV) leading to PbSe film formation ; (ii) solid-state reduction of the PbSe film with the production of m etallic lead; (iii) electrochemical reduction of Se(IV) with the forma tion of elementary selenium. It was shown that stoichiometric PbSe fil m formation with a current efficiency close to 100% takes place when t he ratio of concentrations of selenite and lead ions is equal to 0.5. It was shown that the speed of PbSe formation is limited by the rate o f ion mass transfer of Pb(II) to the electrode surface complicated by a chemical reaction of Se(IV) reduction by metallic lead. The composit ion and structure of as-deposited layers depending on deposition poten tial and bath composition were investigated by different electrochemic al and physical methods.