Huazhong University of Science and Technology - State Key Laboratory of Materials Processing and Die and Mould Technology
Abstract
We report here a high thermoelectric performance in magnesium (Mg) doped Sb2Si2Te6. The substitution of Mg2+ for Sb3+ in Sb2Si2Te6 induces a synergetic effect on electrical transport performance, exciting multi-band carrier transport behavior, enhancing carrier concentration, and increasing the density of states effective mass. Such effects lead to the highest power factor of 10.95 μW cm−1 K−2 at 824 K for the Sb1.99Mg0.01Si2Te6, representing a ∼22% increase compared to pristine Sb2Si2Te6. In addition, Mg doping induces point defects phonon scattering, resulting in a low thermal conductivity of ∼0.52 W m−1 K−1 at 824 K. The simultaneous optimization of the power factor and thermal conductivity in Sb1.99Mg0.01Si2Te6 leads to a peak ZT of ∼1.15 at 824 K and an average ZT of ∼0.68 (400−824 K), showing its potential for power generator at medium temperature.
Li, Chengjun and Luo, Yubo and Li, Wang and Yang, Linhan and Ma, Wenyuan and Ma, Zheng and Sun, Chengwei and Yang, Boyu and Wei, Yingchao and Li, Xin and Yang, Junyou, Enhanced Power Factor and Figure of Merit Through Magnesium Doping in Sb2Si2Te6. Available at SSRN: https://ssrn.com/abstract=4622056 or http://dx.doi.org/10.2139/ssrn.4622056
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