title: Fabrication of Bi2Te3-xSexnanowires with tunable chemical compositions and enhanced thermoelectric properties.
abstract: Uniform Bi2Te3-xSexnanowires (NWs) with tunable components are synthesized by a modified solution method free of any template, and inter-diffusion mechanism is proposed for the growth and transformation of ternary nanowires. Spark plasma sintering is adopted to fabricate the pellets of Bi2Te3-xSexNWs and thermoelectric transport properties are measured. As compared to Bi2Te3pellets, Se doping results in lowered electrical conductivity because of the reduced carrier concentration, both the Seebeck coefficient and the power factor are enhanced substantially. The Bi2Te2.7Se0.3pellet exhibits the highest power factor at room temperature as a result of optimized carrier concentration (4.37 × 1019cm-3) and mobility (60.22 cm2V-1s-1). As compared to Bi2Te3, the thermal conductivity of Bi2Te3-xSexis lowered owing to the enhanced phonon scattering by dopants and grain boundaries. As a result, the ZT value at 300 K is substantially improved from 0.045 of Bi2Te3to 0.42 of Bi2Te2.7Se0.3. It is suggested that Se doping is an effective way to enhance the thermoelectric performance of Bi2Te3based materials.
authors.affiliation: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Liu
authors.forename: Nan
authors.initials: N
authors.lastname: Peng
authors.forename: Chongjian
authors.initials: C
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Shuang
authors.initials: S
authors.lastname: Tang
authors.forename: Dayan
authors.initials: D
authors.lastname: Ma
authors.forename: Fei
authors.initials: F
authors.lastname: Ma
authors.forename: Kewei
authors.initials: K
authors.lastname: Xu