title: Enhanced Thermoelectric Properties in the Counter-Doped SnTe System with Strained Endotaxial SrTe.
abstract: We report enhanced thermoelectric performance in SnTe, where significantly improved electrical transport properties and reduced thermal conductivity were achieved simultaneously. The former was obtained from a larger hole Seebeck coefficient through Fermi level tuning by optimizing the carrier concentration with Ga, In, Bi, and Sb dopants, resulting in a power factor of 21 μW cm(-1) K(-2) and ZT of 0.9 at 823 K in Sn(0.97)Bi(0.03)Te. To reduce the lattice thermal conductivity without deteriorating the hole carrier mobility in Sn(0.97)Bi(0.03)Te, SrTe was chosen as the second phase to create strained endotaxial nanostructures as phonon scattering centers. As a result, the lattice thermal conductivity decreases strongly from ∼2.0 Wm(-1) K(-1) for Sn(0.97)Bi(0.03)Te to ∼1.2 Wm(-1) K(-1) as the SrTe content is increased from 0 to 5.0% at room temperature and from ∼1.1 to ∼0.70 Wm(-1) K(-1) at 823 K. For the Sn(0.97)Bi(0.03)Te-3% SrTe sample, this leads to a ZT of 1.2 at 823 K and a high average ZT (for SnTe) of 0.7 in the temperature range of 300-823 K, suggesting that SnTe is a robust candidate for medium-temperature thermoelectric applications.
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Li-Dong
authors.initials: LD
authors.lastname: Zhao
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Haijun
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Gangjian
authors.initials: G
authors.lastname: Tan
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Pei
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chang
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Physics, University of Michigan , Ann Arbor, Michigan 48109, United States.
authors.forename: Hang
authors.initials: H
authors.lastname: Chi
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
authors.forename: Shengkai
authors.initials: S
authors.lastname: Gong
authors.affiliation: Department of Physics, University of Michigan , Ann Arbor, Michigan 48109, United States.
authors.forename: Ctirad
authors.initials: C
authors.lastname: Uher
authors.forename: Jiaqing
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis