摘要
Defect existing form and its evolution play an important role in the thermoelectric transport process. Here different forms of Pb into the Sn Se system were introduced in order to improve the thermoelectric and mechanical properties of Sn Se. Pb/Sn Se samples were fabricated by vacuum melting, solid phase diffusion,spark plasma sintering and annealing treatment. The element valence mapping diagram and the X-ray photoelectron spectra(XPS) characteristic peaks of Pb show that a certain amount of elemental Pb exists in the initial state, and evolves into Pb^(2+)ion after annealing treatment. The micro-structure evolution leads to significant enhancement of the power factor and the ZT value. The power factor(PF) and the ZT value for Pb/Sn Se increases to 623 μW/m/K^(2) and 1.12 at 773 K after annealing treatment, respectively.Compared with Sn Se matrix, the hardness and fracture toughness of Pb/Sn Se samples increased by about40% and 10%, respectively. Reasonable control of microstructure evolution is expected to be a design idea to improve thermoelectric and mechanical properties of Sn Se.
基金
financially supported by the National Natural Science Foundation of China (No. 51772176)
the Science and Technology Development Project of Shandong Province (No.2019JZZY010303)
the Shandong Natural Science(No. ZR2015EM013)。
