title: Study of the thermoelectric properties of lead selenide doped with boron, gallium, indium, or thallium.
abstract: Group IIIA elements (B, Ga, In, and Tl) have been doped into PbSe for enhancement of thermoelectric properties. The electrical conductivity, Seebeck coefficient, and thermal conductivity were systematically studied. Room-temperature Hall measurements showed an effective increase in the electron concentration upon both Ga and In doping and the hole concentration upon Tl doping to ~7 × 10(19) cm(-3). No resonant doping phenomenon was observed when PbSe was doped with B, Ga, or In. The highest room-temperature power factor ~2.5 × 10(-3) W m(-1) K(-2) was obtained for PbSe doped with 2 atom % B. However, the power factor in B-doped samples decreased with increasing temperature, opposite to the trend for the other dopants. A figure of merit (ZT) of ~1.2 at ~873 K was achieved in PbSe doped with 0.5 atom % Ga or In. With Tl doping, modification of the band structure around the Fermi level helped to increase the Seebeck coefficient, and the lattice thermal conductivity decreased, probably as a result of effective phonon scattering by both the heavy Tl(3+) ions and the increased grain boundary density after ball milling. The highest p-type ZT value was ~1.0 at ~723 K.
authors.affiliation: Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Cao
authors.forename: Kevin
authors.initials: K
authors.lastname: Lukas
authors.forename: Weishu
authors.initials: W
authors.lastname: Liu
authors.forename: Keivan
authors.initials: K
authors.lastname: Esfarjani
authors.forename: Cyril
authors.initials: C
authors.lastname: Opeil
authors.forename: David
authors.initials: D
authors.lastname: Broido
authors.forename: David
authors.initials: D
authors.lastname: Parker
authors.forename: David J
authors.initials: DJ
authors.lastname: Singh
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Ren