Growth of homogeneous polycrystalline Si 1-xGe x and Mg 2Si 1-xGe x for thermoelectric application

• Published in: Thin solid films Vol. 519; no. 24; pp. 8532 - 8537
• Main Authors: Hayakawa, Yasuhiro, Arivanandhan, Mukannan, Saito, Yosuke, Koyama, Tadanobu, Momose, Yoshimi, Ikeda, Hiroya, Tanaka, Akira, Wen, Cuilian, Kubota, Yoshihiro, Nakamura, Tamotsu, Bhattacharya, Shovit, Aswal, Dinesh Kumar, Babu, Sridharan Moorthy, Inatomi, Yuko, Tatsuoka, Hirokazu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2011
• Subjects: Growth from solutions; Magnesium Silicon Germanium; Silicon Germanium alloys; Thermoelectric property; Growth from solutions; Thermoelectric property; Magnesium Silicon Germanium; Silicon Germanium alloys
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.05.033

Homogeneous polycrystalline Si 1-xGe x were grown using a Si(seed)/Ge/Si(feed) sandwich structure under the low temperature gradient less than 0.4 °C/mm. It was found that the composition of the Si 1-xGe x was controlled by the growth temperature. The homogeneous Mg 2Si 1-xGe x was synthesized by heat treatment of the homogeneous Si 1-xGe x powders under Mg vapor. The Mg 2Si 1-xGe x sample with the relative density of 95% was synthesized by spark plasma sintering technique. The resistivity and the Seebeck coefficient of the Si, Ge, Si 1-xGe x and Mg 2Si 1-xGe x samples were evaluated as a function of temperature. It indicated that Seebeck coefficients of the Si 1-xGe x and Mg 2Si 1-xGe x samples were higher than those of Si and Ge. Moreover, the Seebeck coefficient of Mg 2Si 0.7Ge 0.3 sample was higher than that of Mg 2Si 0.5Ge 0.5 and Si 0.5Ge 0.5 samples.