Electrodeposition of CdTe films from ammoniacal alkaline aqueous solution at low cathodic overpotentials
- Kyoto Univ. (Japan). Dept. of Materials Science and Engineering
Cathodic electrodeposition of CdTe films was studied using aqueous ammonia-alkaline electrolytic baths (pH 10.7; temperature 343 K) in which Cd(II) and Te(IV) species were dissolved to form Cd(NH{sub 3}){sub 4}{sup 2+} and TeO{sub 3}{sup 2{minus}} ions, respectively. From the solution, 60 mM Cd(II)-10 mM Te(IV)-4.0 M NH{sub 3}-1.0 M NH{sub 4}{sup +} (M = mol dm{sup {minus}3}), a flat and smooth polycrystalline CdTe film (thickness, ca. 1 {micro}m) with nearly stoichiometric composition was deposited at a constant cathode potential, ranging from {minus}0.70 to {minus}0.30 V vs. SHE, whereas dendrite CdTe accompanying elemental cadmium was obtained at {minus}0.80 V. The deposition behavior was fully explained by an underpotential deposition mechanism taking the calculated redox potentials of Te{sup 0}/Te{sup IV}O{sub 3}{sup 2{minus}} and Cd{sup 0}/Cd{sup II}(NH{sub 3}){sub 4}{sup 2+} pairs into consideration. During electrodeposition of nearly stoichiometric crystalline CdTe, the current density was decreasing monotonously.
- OSTI ID:
- 328211
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 146; ISSN JESOAN; ISSN 0013-4651
- Country of Publication:
- United States
- Language:
- English
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