论文部分内容阅读
(In2Te3)x(SnTe)1-x系列化合物具有较低的电导率和热导率,热电性能较差。考虑到其中的In2Te3单元具有三分之一的阳离子空位,可以通过掺杂Cu等外来原子来占据In的空位,使化合物的载流子浓度达到最优化,降低材料的热导率从而改善其热电性能。本组实验中,采用真空熔炼、机械球磨及放电等离子烧结技术制备了(In2-x Cux Te3)0.08(SnTe)0.92(x=0.025,0.05,0.2)系列化合物。测试结果表明,掺杂不同摩尔数的Cu元素后,材料的Seebeck系数几乎没有变化,电导率有所提高,晶格热导率L值大幅度降低,成功地抑制了高温区(In2Te3)0.08(SnTe)0.92的双极扩散效应。当x=0.2时,该化合物在647 K取得最大ZT值0.29,是掺杂Cu元素前ZT值的4.6倍。
(In2Te3) x (SnTe) 1-x series compounds have lower conductivity and thermal conductivity and poor thermoelectric properties. Taking into account that the In2Te3 unit has one-third of the cationic vacancies, it can be doped with Cu and other foreign atoms to occupy the vacancies of In, so that the compound carrier concentration to achieve the best to reduce the thermal conductivity of the material to improve its thermoelectric performance. In this experiment, a series of In2-xCuxTe3 0.08 (SnTe) 0.92 (x = 0.025,0.05,0.2) compounds were prepared by vacuum melting, mechanical milling and spark plasma sintering. The results show that the Seebeck coefficient of the material has almost no change after doped with different molar Cu, the conductivity is increased, the L value of lattice thermal conductivity is greatly reduced, and the In2Te3 0.08 SnTe) 0.92 bipolar diffusion effect. When x = 0.2, the maximum ZT value of the compound at 647 K was 0.29, which was 4.6 times the ZT value before the Cu element was doped.