15852-22-9Relevant articles and documents
Galvanic contact deposition of CdTe layers using ammoniacal basic aqueous solution
Arai, Kentaro,Hagiwara, Souichi,Murase, Kuniaki,Hirato, Tetsuji,Awakura, Yasuhiro
, p. C237-C242 (2008/10/09)
The galvanic contact deposition of CdTe layers from ammoniacal basic solutions was carried out, and their deposition behaviors were investigated. The structural and electrical properties of deposits were examined and then compared with those of deposits prepared by normal electrodeposition from the same solutions. The cathode potential was always spontaneously kept at around -0.7 V vs. standard hydrogen electrode during the contact deposition although CdTe also deposited on the Cd sheet, that is, the anode. The current density gradually decreased with time just like that in the normal potentiostatic electrodeposition. The current efficiency was approximately 100% under illumination, whereas it was less than 50% in the dark. These behaviors were the same as those observed in normal electrodeposition from the same electrolytes. The resulting deposits both under illumination and in the dark were polycrystalline CdTe layers with almost stoichiometric composition. The as-deposited CdTe layer had a p-type conduction with resistivity of the order of 107 Ω cm.
Tellurium(V). A pulse radiolysis study
Klaening,Sehested
, p. 6637 - 6645 (2007/10/03)
Four different tellurium(V) oxoradicals, assumed to be H2TeO4-, TeO3-, HTeO42-, and TeO43-, were detected by the pulse radiolysis technique. H2TeO4- is the product of the reaction of OH with HTeO3-, whereas HTeO42- and TeO43- arise by reactions of OH and O- with the TeO32-. TeO3- is a secondary product formed by dehydration of H2TeO4-, a process catalyzed by HTeO3-. The same tellurium(V) species except H2TeO4- are formed by reaction of the hydrated electron with H6TeO6, H5TeO6-, and H4TeO62-. The spectra, kinetics of the reactions of the tellurium(V) species, the acidity constant of HTeO42- (～10-13), and the apparent acidity constant of TeO3- (10-10) have been measured. The standard Gibbs energies of formation ΔfGao°(TeO3-) = -214 kJ/mol, ΔfGao°(HTeO42-) = -394 kJ/mol, and ΔfGao°(TeO43-) = -319 kJ/mol were determined from the rate constants for the forward and reverse reactions TeO32- + O- ? TeO43- and TeO32- + OH ? HTeO42-, combined with the acidity constants of TeO3- and HTeO42- and the standard Gibbs energy of formation of OH, O-, and TeO32-. TeO3- is a strong reducing agent (Eo(red) = -0.40 V), which appears to reduce O2, as well as a strong oxidant (Eo(ox) = 1.74 V), oxidizing CO32- to CO3-.
THERMODYNAMIC EQUILIBRIA OF SULFUR, SELENIUM AND TELLURIUM WATER SYSTEMS IN RANGE OF TEMPERATURES FROM 25 TO 300 C AND THEIR GEOCHEMICAL INTERPRETATION
D'YACHKOVA IB,KHODAKOVSKII IL
, p. 1358 - 1375 (2008/10/08)
Thermodynamic analysis of Eh-pH stability fields shows that separation stage of sulfur, selenium, and tellurium from solutions may be determined by Eh-pH factors and temperature changes; Eh of environment is most important factor. Maximum separation of th
