ELECTRODEPOSITION OF CUINSE2 THIN-FILMS FROM AQUEOUS CITRIC SOLUTIONS .2. INVESTIGATION OF MACROKINETICS OF ELECTRODEPOSITION BY MEANS OF ROTATING-DISK ELECTRODE

Investigations of the macrokinetics of electrodeposition from citric aqueous solutions containing Cu(II), In(III) and se(IV) show that the rate of electrodeposition is determined by mixed kinetics (ion mass transfer complicated by a chemical reaction), independent of which compound is formed (CuSe, Cu(3)s(2), CuInSe2). It was shown that the chemical reaction determining the common rate of electrodeposition is SeO32- reduction by metallic copper. The reaction constant k = (2.5 +/- 0.2)10(-2) cm s(-1) was determined experimentally. It was shown that the diffusion stage of CuSe and Cu3Se2 formation is determined by the speed of ion mass transfer of Cu(II). When Cu3Se2, is formed the possible low surface concentration of copper determined by the slow heterogeneous chemical reaction of Se(IV) reduction by copper is achieved. Over this region of potentials In(III) began to interact with Cu3Se2 to produce CuInSe2. The diffusion stage of this process is determined by the rate of ion mass transfer of Se(IV).