The Electronic Transport Channel Protection and Tuning in Real Space to Boost the Thermoelectric Performance of Mg3+δSb2-yBiy near Room Temperature
Zhijia Han,
Zhigang Gui,
Y. B. Zhu,
Peng Qin,
Bo-Ping Zhang,
Wenqing Zhang,
Li Huang,
Weishu Liu
Affiliations
Zhijia Han
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 10083, China
Zhigang Gui
Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China
Y. B. Zhu
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Peng Qin
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Bo-Ping Zhang
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 10083, China
Wenqing Zhang
Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
Li Huang
Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
Weishu Liu
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China
The optimization of thermoelectric materials involves the decoupling of the transport of electrons and phonons. In this work, an increased Mg1-Mg2 distance, together with the carrier conduction network protection, has been shown as an effective strategy to increase the weighted mobility (U=μm∗3/2) and hence thermoelectric power factor of Mg3+δSb2-yBiy family near room temperature. Mg3+δSb0.5Bi1.5 has a high carrier mobility of 247 cm2 V-1 s-1 and a record power factor of 3470 μW m-1 K-2 at room temperature. Considering both efficiency and power density, Mg3+δSb1.0Bi1.0 with a high average ZT of 1.13 and an average power factor of 3184 μW m-1 K-2 in the temperature range of 50-250°C would be a strong candidate to replace the conventional n-type thermoelectric material Bi2Te2.7Se0.3. The protection of the transport channel through Mg sublattice means alloying on Sb sublattice has little effect on electron while it significantly reduces phonon thermal conductivity, providing us an approach to decouple electron and phonon transport for better thermoelectric materials.
