title: Enhanced Average Thermoelectric Figure of Merit of the PbTe-SrTe-MnTe Alloy.
abstract: Thermoelectric properties of Na-doped PbTe-SrTe system have been improved by the addition of Mn. The substitution of Mn for Pb modifies the band structure of the PbTe-SrTe alloy, which enlarges the band gap and increases the valence band degeneracy. This leads to increased thermopowers and power factors near room temperature, and the electronic contribution to the total thermal conductivity is also substantially reduced due to increased resistivity. Moreover, alloying of MnTe within the PbTe matrix introduces low angle grain boundaries, and significantly reduces the lattice thermal conductivity due to the dislocation scattering. A thermoelectric figure of merit as high as 1.98 and an enhancement of the average thermoelectric figure of merit by 18% are achieved for the sample with 4 at% Mn with respect to the Mn-free sample, which can be mainly attributed to the synergistic effects of the band structure modification and the dislocation scattering on phonon transport, both induced by alloying with MnTe. Our experimental results demonstrate the promising potential of PbTe-SrTe-MnTe system for the application of waste heat recovery.
authors.affiliation: School of Materials Science and Engineering, Shanghai University , 99 Shangda Road, Shanghai 200444, China.|Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Jun
authors.identifier: http://orcid.org/0000-0002-8235-2338
authors.initials: J
authors.lastname: Luo
authors.affiliation: School of Materials Science and Engineering, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Li
authors.initials: L
authors.lastname: You
authors.affiliation: School of Materials Science and Engineering, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Jiye
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Guo
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Hangtian
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.|Collaborative Innovation Center of Quantum Matter , Beijing 100190, China.|School of Physical Sciences, University of Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Lin
authors.identifier: http://orcid.org/0000-0002-7504-031X
authors.initials: L
authors.lastname: Gu
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Jiong
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, Shanghai University , 99 Shangda Road, Shanghai 200444, China.|Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Zhang
keywords: PbTe; band gap; edge dislocation; lattice thermal conductivity; low angle grain boundary; thermoelectric materials