• Horichok, Ihor
• Mori, Takao
• Muchtar, Ahmad Rifqi
• Dashevsky, Zinovi
• Maksymuk, Mykola

Abstract

<jats:title>Abstract</jats:title><jats:p>GeTe is a promising candidate for the fabrication of high‐temperature segments for <jats:italic>p</jats:italic>‐type thermoelectric (TE) legs. The main restriction for the widespread use of this material in TE devices is high carrier concentration (up to ∼ 10<jats:sup>21</jats:sup> cm<jats:sup>−3</jats:sup>), which causes the low Seebeck coefficient and high electronic component of thermal conductivity. In this work, the band structure diagram and phase equilibria data have been effectively used to attune the carrier concentration and to obtain the high TE performance. The Ge<jats:sub>1−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>Bi<jats:italic><jats:sub>x</jats:sub></jats:italic>Te (<jats:italic>x</jats:italic> = 0.04) material prepared by the Spark plasma sintering (SPS) technique demonstrates a high power factor accompanied by moderate thermal conductivity. As a result, a significantly higher dimensionless TE figure of merit <jats:italic>ZT</jats:italic> = 2.0 has been obtained at ∼ 800 K. Moreover, we are the first to propose that application of the developed Ge<jats:sub>1−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>Bi<jats:italic><jats:sub>x</jats:sub></jats:italic>Te (<jats:italic>x</jats:italic> = 0.04) material in the TE unicouple should be accompanied by SnTe and CoGe<jats:sub>2</jats:sub> transition layers. Only such a unique solution for the TE unicouple makes it possible to prevent the negative effects of high contact resistance and chemical diffusion between the segments at high temperatures.</jats:p>

Topics

• impedance spectroscopy
• phase
• thermal conductivity
• band structure
• sintering