Thermoelectric Properties of Ultralong Silver Telluride Hollow Nanofibers

详细信息    查看全文

• 作者：Miluo Zhang ; Hosik Park ; Jiwon Kim ; Hyounmyung Park ; Tingjun Wu ; Seil Kim ; Su-Dong Park ; Yongho Choa ; Nosang V. Myung
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：August 11, 2015
• 年：2015
• 卷：27
• 期：15
• 页码：5189-5197
• 全文大小：450K
• ISSN：1520-5002

文摘

Ultralong Ag_xTe_y nanofibers were synthesized for the first time by galvanically displacing electrospun Ni nanofibers. Control over the nanofiber morphology, composition, and crystal structure was obtained by tuning the Ag⁺ concentrations in the electrolytes. While Te-rich branched p-type Ag_xTe_y nanofibers were synthesized at low Ag⁺ concentrations, Ag-rich nodular Ag_xTe_y nanofibers were obtained at high Ag⁺ concentrations. The Te-rich nanofibers consist of coexisting Te and Ag₇Te₄ phases, and the Ag-rich fibers consist of coexisting Ag and Ag₂Te phases. The energy barrier height at the phase interface is found to be a key factor affecting the thermoelectric power factor of the fibers. A high barrier height increases the Seebeck coefficient, S, but reduces the electrical conductivity, 蟽, due to the energy filter effect. The Ag₇Te₄/Te system was not competitive with the Ag₂Te/Ag system due to its high barrier height where the increase in S could not overcome the severely diminished electrical conductivity. The highest power factor was found in the Ag₂Te/Ag-rich nanofibers with an energy barrier height of 0.054 eV.