The characterization of prepared thermoelectric materials Sb2Te3 and Bi2Te3 by electrochemical deposition

• Main Authors: Yu-Hsuan Lin, 林雨萱
• Other Authors: Chin-Ming Chu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/89906465566064125463

碩士 === 國立聯合大學 === 化學工程學系碩士班 === 99 === Bismuth telluride、antimony telluride and their derivative compounds are narrow band-gap semiconductors with good thermo- electric characteristics at room temperature . Their thermoelectric nature depends on their composition . Bi2Te3 and Sb2Te3 are widely used for biomedical、 thermoelectric、optoelectronic fields and solar cell and so on . In this paper , we change different parameters (temperature、composition of solution、 stirring) to codeposit thermoelectric powders by electro- chemical deposition (ECD) in aqueous systems . We can known the electrochemical behavior of the binary alloy Bi/Te and Sb/Te is known by cyclic voltametry . HTeO2 + in tartaric acid, there are two reduction peaks,This means that Te has two reduction mechanisms by cyclic voltammogram . We use SEM、EDS、XRD to analyze the morphology、composition and know that the crystalline phases of BixTey and SbxTey are in the (0 1 5) preferred orientation having a good surface . Finally,we use the instrument CHI-440 (EQCM) to analyze electrochemical deposition mechanism after adding tartaric acid as a chelating agent for progressive nucleation mechanism, while for instaneous mechanism without tartaric acid. Electrochemical performance efficiency is about 78%.