Electrochemical and structural investigation of BixTey thin films electrodeposited on ITO substrate

Autor: Boubaker. Youbi, Youssef. Lghazi, Mohammed. Ait Himi, Aziz. Aynaou, Jihane. Bahar, Chaimaa. El Haimer, Abdessamad. Ouedrhiri, Ahmed Sahlaoui, Itto. Bimaghra
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Applied Surface Science Advances, Vol 16, Iss , Pp 100419- (2023)
Druh dokumentu: article
ISSN: 2666-5239
DOI: 10.1016/j.apsadv.2023.100419
Popis: Bismuth telluride films with various stoichiometries BixTey have been successfully elaborated by potentiostatic deposition on indium tin oxide (ITO) substrate from an acidic solution containing a mixture of different concentrations of Bi3+ and HTeO2+ ions. The electrochemical study using cyclic voltammetry and chronoamperometry shows that the electrodeposition of bismuth telluride is a quasi-reversible reaction controlled by the diffusion process and the composition of the reaction mixture controls the BixTey stoichiometry. It was found, from electrochemical and EDS analysis, that a mixture in stoichiometric proportions leads to the formation of bismuth tellurium Bi2Te3, an excess of telluryl ion HTeO2+ gives a product rich in tellurium Bi2-xTe3+x, but a high concentration of Bi3+ (compared to the stoichiometry) gives rise to the electrodeposition of a compound rich in bismuth Bi2+xTe3-x. The chronoamperometric analysis of current density-time transients using Scharifker-Hills model showed that the mechanism of deposition and growth of BixTey on ITO substrate takes place according to a progressive 3D nucleation for low Bi3+ concentration and 3D instantaneous nucleation for higher concentration. The morphology of the BixTey films is strongly depending to the electrolytes composition. The X-ray diffraction characterization shows that the crystalline structure of bismuth tellurium BixTey produced is of the rhombohedral type.
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