title: Effect of silicon and sodium on thermoelectric properties of thallium-doped lead telluride-based materials.
abstract: Thallium (Tl)-doped lead telluride (Tl(0.02)Pb(0.98)Te) thermoelectric materials fabricated by ball milling and hot pressing have decent thermoelectric properties but weak mechanical strength. Addition of silicon (Si) nanoparticles strengthened the mechanical property by reducing the grain size and defect density but resulted in low electrical conductivity that was not desired for any thermoelectric materials. Fortunately, doping of sodium (Na) into the Si added Tl(0.02)Pb(0.98)Te brings back the high electrical conductivity and yields higher figure-of-merit ZT values of ∼1.7 at 770 K. The ZT improvement by Si addition and Na doping in Tl(0.02)Pb(0.98)Te sample is the direct result of concurrent electron and phonon engineering by improving the power factor and lowering the thermal conductivity, respectively.
authors.affiliation: School of Material Science and Engineering, Xihua University, Chengdu, Sichuan 610039, PR China.
authors.forename: Qinyong
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hengzhi
authors.initials: H
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Weishu
authors.initials: W
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Dezhi
authors.initials: D
authors.lastname: Wang
authors.forename: George
authors.initials: G
authors.lastname: Ni
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Ren