典型单相块体热电材料性能优化设计的实验检验

CoSb3、Bi2Te3以及half-Hueseler体系是三类典型的单相块体热电化合物，近些年来，人们在声子玻璃-电子晶体理念指导下，通过复合、填充等手段引入多重局域效应使其声子的热导降低到接近于理论的极限,复合材料的效率大幅提高。效率的进一步提高依赖于电导率和Seebeck协调提高，人们在此问题上做了有益的尝试，取得了一定的成果。我们在前期工作中，从体系能带结构出发，给出了三个单相化合物的热电功率因子、或热电优值随温度变化的规律，并给出了最佳功率因子或热电优值对应的多种可能的n型及p型掺杂替代元素和相应浓度。本项目就是希望对前述材料的理论设计进行实验检验，以期找到几个本征热电性能优异的母相材料，并进一步的对其复合改性，降低热导，探索制备出几个热电综合性能协调，热电优值高的复合材料。

CoSb3、Bi2Te3，and half-Hueseler system are three typical alloy compounds of single phase. Recently, the multiple-localization effects by means of materials composite and atoms filling induce their thermal conductivity to decrease into a theoretical limit, and the thermoelectric efficiency to increase greatly. The further increase of the efficiency depends on integrated enhance of electronic conductivity and Seebeck coefficient, much studies have performed on it. Within the framework of energy band and Boltzmann theory, our theoretical calculations have given the power factors and ZT values as the functions of chemical potential of three kinds of the compounds. Meanwhile, the several possible doping or substitution elements and concentrations corresponding to the optimum power factors and ZT values are predicted both as n and p types materials, respectively. Within this project, we wish to perform some experimental investigations according on above theoretical design, in order to get several instinct single phase compounds with fine thermoelectric properties. Moreover, based on these mother compounds, we wish to introduce some composite phase to decrease thermal conductivity, in finally, to acquire several composites with higher ZT values.