724 ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 6, pp. 724−729. © Pleiades Publishing, Ltd., 2014. Original Russian Text © M.B. Dergacheva, K.A. Urazov, K.A. Leont’eva, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 6, pp. 732−737. APPLIED ELECTROCHEMISTRY AND CORROSION PROTECTION OF METALS Formation of tellurium deposits and thin-film tel- lurium coatings is important for manufacture of thin- film photocells. The keen interest of researchers in the fabrication and use of thin-film tellurium-containing semiconductor compounds, such as CdTe, ZnTe, PbTe, Cd x Hg 1–x Te, in photovoltaic devices is due to the fact that these compounds have a favorable energy gap width suitable for solar light conversion. One of promising ways to obtain thin-film semi- conductor compounds is by the photochemical method [1–3]. However, techniques for photoelectrodeposition of thin films of semiconductors have been little studied, only a small number of studies concerned with the electrodeposition of semiconductors under illumination are known [4–7]. Most part of methods used to obtain thin films and nanocrystals of metal sulfides, selenides, and tellurides are based either on photodecomposition of complexes including ions of a metal and chalcogenide, or on photoreduction of sulfur-, selenium-, and tellurium- containing compounds from a solution containing metal salts [6]. The electrochemical behavior of Te(IV) ions in reduction on solid electrodes in acid aqueous media is mostly determined by two stages [8–11]: reduction to the elementary metal(Te0) and further to divalent telluride ions (Te 2– ) by the reactions Te(IV) + 4e → Te 0 , (1) Te 0 + 2e → Te 2– . (1a) At the same time, it is known that, absorbing a photon under illumination, tellurium can generate telluride ions by the reaction Te 0 + hν → Te 2– . (2) This ability can be used to obtain compounds of cad- mium chalcogenides by chemical reactions Te 0 + hν → Te 2– + Cd 2+ → CdTe. (3) The goal of our study was to examine the effect of illumination on the electrochemical behavior of Te(IV) ions in sulfuric-acid solutions and on the electrodeposi- tion of tellurium onto a glassy carbon electrode in order to prepare thin-film telluride electrodes. Photoelectrochemical Deposition of Thin Tellurium Films M. B. Dergacheva, K. A. Urazov, and K. A. Leont’eva Sokol’skii Institute of Organic Catalysis and Electrochemistry, ul. Kunaeva 142, Almaty, 050010 Kazakhstan e-mail: m_dergacheva@mail.ru Received May 23, 2014 Abstract—Effect of polychromatic light on the electrochemical deposition of tellurium(IV) ions on a glass carbon electrode from acid solutions of 0.45 M Na 2 SO 4 + 0.05 M H 2 SO 4 with pH 2.2 was studied. It is shown that electrochemical reduction of tellurium(IV) is possible in two stages in the potentiodynamic mode at potentials in the range from 0 to –1000 mV. Elementary tellurium is formed in the first stage (E = –320 ± 20 mV) and is reduced to telluride ions in the second (E = –700 ± 50 mV). It is demonstrated that, under potentiodynamic deposition conditions, visible light affects the generation of Te 2– ions at potentials more positive than the electrochemical potential. The chronoamperometric method revealed differences in the behavior of transient currents in the dark and under illumination. The elemental composition and the film surface morphology were studied by electron- probe analysis. DOI: 10.1134/S107042721406010X