Material parameters for thermoelectric performance

Pramana

M N Tripathi1 2¹  C M Bhandari3² 

[1] Department of Physics, University of Allahabad, Allahabad 211 002, India$$;Indian Institute of Information Technology, Allahabad 211 002, India$$

关键词: Semiconductors;    thermoelectric materials;    figure-of-merit.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The thermoelectric performance of a thermoelement is ideally defined in terms of the so-called figure-of-merit 𝑍 = 𝛼2 𝜎/ 𝜆, where 𝛼, 𝜎 and 𝜆 refer respectively to the Seebeck coefficient, electrical conductivity and thermal conductivity of the thermoelement material. However, there are other parameters which are fairly good indicators of a material's thermoelectric `worth'. A simple yet useful performance indicator is possible with only two parameters-energy gap and lattice thermal conductivity. This indicator can outline all potentially useful thermoelectric materials. Thermal conductivity in place of lattice thermal conductivity can provide some additional information about the temperature range of operation. Yet another performance indicator may be based on the slope of 𝛼 vs. ln 𝜎 plots. 𝛼 plotted against ln 𝜎 shows a linear relationship in a simplified model, but shows a variation with temperature and carrier concentration. Assuming that such a relationship is true for a narrow range of temperature and carrier concentration, one can calculate the slope 𝑚 of 𝛼 vs. ln 𝜎 plots against temperature and carrier concentrations. A comparison between the variation of 𝑍𝑇 and slope 𝑚 suggests that such plots may be useful to identify potential thermoelectric materials.

【 授权许可】

Unknown