Journal article

Publication year: 2016

Pages: 273-280

Journal: Acta Materialia

Volume number: 120

ISSN: 1359-6454

eISSN: 1873-2453

Open access status: Green

DOI Link: https://doi.org/10.1016/j.actamat.2016.08.057

Publisher: Elsevier

Abstract: 
Solid solutions with chemical formula Mg-2(Si,Ge,Sn) are promising thermoelectric materials with very good properties for the n-type material but significantly worse for the p-type. For power generation applications good n- and p-type materials are required and it has been shown recently that Li doping can enhance the carrier concentration and improve the thermoelectric properties for p-type Mg2Si1-xSnx. We have investigated the potential of p-type Mg-2(Ge,Sn) by optimizing Mg2Ge0.4Sn0.6 using Li as dopant. We were able to achieve high carrier concentrations (1.4 x 10(20) cm(-3)) and relatively high hole mobilities resulting in high power factors of 1.7 x 10(-3) W m(-1) K-2 at 700 K, the highest value reported so far for this class of material. Exchanging Ge by Si allows for a systematic comparison of Mg-2(Ge,Sn) with Mg-2(Si,Sn) and shows that Si containing samples exhibit a lower power factor but also a lower thermal conductivity resulting in comparable thermoelectric figure-of-merit. The data is furthermore analyzed in the framework of a single parabolic band model to gain insight on the effect of composition on band structure. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Harvard Citation style: de Boor, J., Saparamadu, U., Mao, J., Dahal, K., Mueller, E. and Ren, Z. (2016) Thermoelectric performance of Li doped, p-type Mg₂(Ge,Sn) and comparison with Mg₂(Si,Sn), Acta Materialia, 120, pp. 273-280. https://doi.org/10.1016/j.actamat.2016.08.057

APA Citation style: de Boor, J., Saparamadu, U., Mao, J., Dahal, K., Mueller, E., & Ren, Z. (2016). Thermoelectric performance of Li doped, p-type Mg₂(Ge,Sn) and comparison with Mg₂(Si,Sn). Acta Materialia. 120, 273-280. https://doi.org/10.1016/j.actamat.2016.08.057