论文标题
基于粉末的热电材料的热emf
ThermoEMF of powder-based thermoelectric materials
论文作者
论文摘要
在论文中，计算基于粉末的热电材料（TEM）的热emf。计算是根据平均自由路径对能量的幂依赖性的假设进行的。随着粉末颗粒的平均半径的增加，热eemf的降低，但是，它随着平均松弛时间对能量的平均自由途径的依赖性定律的增加而大大增加。因此，事实证明，具有较高散射指数的基于粉末的TEM的热emf可能比具有低散射指数的单晶材料的热emf大。因此，只有在粉末颗粒之间的介电或真空屏障不会导致电导率显着降低时，才可以预期，在进入粉末材料中的热电学功绩，尤其是在变粉末材料中的热量优点，尤其是在粉末材料中的优点，尤其是在粉末材料中的优点，尤其是在粉末材料中的优点，尤其是在变粉末材料中的优点，尤其是在粉末材料中的优点，尤其是在粉末材料中的优点，尤其是在粉末材料中的功绩显着增加。同时，通过上述屏障的隧道应提供这种电荷载体的能量过滤，这既导致具有大于化学电位的“有用”荷载体的比例增加，又会增加散射指数的增加。但是，在实验上，从单晶材料到粉末，热eemf没有显着增加，这很可能是因为这种能量过滤不会发生。
In the paper, the thermoEMF of powder-based thermoelectric materials (TEM) is calculated. The calculation is made on the assumption of power dependence of mean free path on energy. The thermoEMF decreases with increasing the average radius of powder particles, however, it drastically increases with an increase in power exponent in the law of dependence of the mean free path of relaxation time on energy (scattering index). Therefore, it turns out that the thermoEMF of powder-based TEM with a higher scattering index can be even greater than the thermoEMF of a single-crystal material with a low scattering index. As a consequence, a significant increase in the thermoEMF and, hence, in the thermoelectric figure of merit of TEM in going to powder materials, especially in the case of degenerate electron gas, can be expected only if dielectric or vacuum barriers between powder particles do not lead to a significant decrease in electrical conductivity. At the same time, tunnelling through the abovementioned barriers should provide such an energy filtration of charge carriers, which leads both to an increase in the proportion of "useful" charge carriers with energy greater than the chemical potential, and to an increase in the scattering index. However, experimentally, there is no significant increase in thermoEMF in going from single-crystal materials to powders, most likely because such energy filtering does not take place.
