Fabrication of Nanostructured Thermoelectric Bismuth Telluride Thick Films by Electrochemical Deposition
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- 作者：Shanghua Li ; Muhammet S. Toprak ; Hesham M. A. Soliman ; Jian Zhou ; Mamoun Muhammed ; Dieter Platzek ; Eckhard Mü ; ller
- 刊名：Chemistry of Materials
- 出版年：2006
- 出版时间：August 8, 2006
- 年：2006
- 卷：18
- 期：16
- 页码：3627 - 3633
- 全文大小：657K
- 年卷期：v.18,no.16(August 8, 2006)
- ISSN：1520-5002
文摘
Bismuth telluride (Bi2Te3)-based solid solutions are state-of-the-art thermoelectric (TE) materials forcooling applications at room temperature with a high figure of merit ZT. Nanostructured TE bismuthtelluride thick films have been fabricated by electrodeposition from a solution containing bismuth nitrateand tellurium dioxide in 1 M nitric acid onto gold-sputtered aluminum substrates. A conventional three-electrode cell was used with a platinum sheet as the counter electrode and a saturated calomel electrode(SCE) as the reference electrode. Ethylene glycol (EG) was added to the electrolyte in order to increasethe thickness of the deposited films, and its effect on the structure, morphology, and compositionalstoichiometry of the deposited film was investigated. SEM and XRD were used for structural andcompositional characterization. Bismuth telluride films with thicknesses of ca. 350 
m, a stoichiometriccomposition of Bi2Te3, and a hexagonal crystal structure were obtained. A microprobe technique wasused to measure the lateral Seebeck coefficient in several samples. The free-standing films were shownto be of high homogeneity, where the abundance distribution of the Seebeck coefficient showed a halfwidth of less than 1 V K-1 and a high electrical conductivity of around 450 S cm-1 at room temperature.
m, a stoichiometriccomposition of Bi2Te3, and a hexagonal crystal structure were obtained. A microprobe technique wasused to measure the lateral Seebeck coefficient in several samples. The free-standing films were shownto be of high homogeneity, where the abundance distribution of the Seebeck coefficient showed a halfwidth of less than 1 V K-1 and a high electrical conductivity of around 450 S cm-1 at room temperature.