Theoretical study of thermoelectric properties of n-type doped Mg₂Si_0.4Sn_0.6 solid solutions

Abstract

In this work, a systematic theoretical investigation of thermoelectric properties of n-type doped solid solutions with is presented in the temperature range  K. Electronic transport properties (, S, and ) are calculated using the nearly-free-electron approximation and the Fermi–Dirac statistics. Thermal transport properties including contributions from carriers (), electron–hole pairs () and phonons () computed using the Wiedemann–Franz law, Price’s theory and Srivastava’s scheme, respectively. In a very good agreement with available experimental measurements, among with samples, the highest value for thermoelectric figure of merit ZT is found to be 1.41 at 800 K for sample owing to its highest electrical conductivity and the lowest lattice thermal conductivity values. Additionally, by theoretically considering the doping levels as , we suggest that at 800 K ZT goes up by 30% for sample with the value of compared to sample due to increment in the electrical conductivity and additional mass defect effects to the phonon thermal conductivity.

Keywords:

• Thermoelectricity
• electronic and thermal transport properties
• thermoelectric figure of merit
• phonon scattering mechanisms

Notes

No potential conflict of interest was reported by the author.

Additional information

Funding

This work was supported by the Scientific and Technical Research Council of Turkey (TUBITAK) [grant number 115F387].