ELECTROCHEMICAL DEPOSITION OF PBSE THIN-FILMS FROM AQUEOUS-SOLUTIONS

Electrode processes taking place under cathode polarization in an electrolyte bath containing Pb(II), Se(TV), acetic acid and EDTA were investigated. It was shown that the I-V curve has three characteristic regions: (i) catalytic reduction of Se(IV) leading to PbSe film formation; (ii) solid-state reduction of the PbSe film with the production of metallic lead; (iii) electrochemical reduction of Se(IV) with the formation of elementary selenium. It was shown that stoichiometric PbSe film formation with a current efficiency close to 100% takes place when the 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 of ion mass transfer of Pb(II) to the electrode surface complicated by a chemical reaction of Se(IV) reduction by metallic lead. The composition and structure of as-deposited layers depending on deposition potential and bath composition were investigated by different electrochemical and physical methods.