Possible enhancement of thermoelectric performance for Si-SiO2 sintered composite by percolation effect
Possible enhancement of thermoelectric performance for Si-SiO2 sintered composite by percolation effect
复制标题
通过渗流效应可能增强 Si-SiO2 烧结复合材料的热电性能
DOI：
10.1016/j.jallcom.2020.157919
复制
发表时间：
2021
影响因子：
6.2
通讯作者：
Kohei Kamoya
中科院分区：
文献类型：
--
作者：
Shigeru Katsuyama;Kohei Kamoya
制备了由p型Si0.99B0.01和绝缘SiO2颗粒组成的烧结复合材料，并对其热电性能进行了研究。复合材料的导热系数κ的对数随Si_（0.99）B_（0.01）体积分数的增加几乎呈线性增加，而导电系数σ的对数在Si_（0.99）B_（0.01）体积分数为40%时呈现出快速增加的趋势，之后又逐渐增加。复合材料的导电行为可以理解为由于Si 0.99 B 0.01颗粒的渗流现象，这是由于烧结体中Si 0.99 B 0.01颗粒的导电路径连接完成而引起的。σ/κ值随Si 0.99B 0.01体积分数的增加而增加，当Si 0.99B 0.01体积分数为80%以上时，σ/κ值几乎不变。80%Si_（0.99）B_（0.01）样品在1073 K时的最大无量纲优值ZT为0.23。在有效介质近似下对实验结果进行了讨论，有效介质近似较好地再现了渗流现象。
A sintered composite consisting ofp-type Si0.99B0.01and insulative SiO2particles was fabricated and its thermoelectric properties were investigated. The logarithm of the thermal conductivity,κ, of the composites increases almost linearly with an increase of the volume fraction of Si0.99B0.01, but that of the electrical conductivity,σ, of the composites shows a tendency to increase rapidly when the volume fraction of Si0.99B0.01is 40%, and then gradually increase. The behavior of the electrical conductivity for the composite can be understood as being due to the percolation phenomenon of Si0.99B0.01particle, which is caused by the completion of connection of conductive paths of Si0.99B0.01particles in the sintered body. The value ofσ/κincreases with an increase of the volume fraction of Si0.99B0.01, and becomes almost constant when the volume fraction of Si0.99B0.01is 80% or more. A maximum dimensionless figure of merit,ZT, of 0.23 was obtained for the sample of 80% Si0.99B0.01at 1073K. The experimental results were discussed based on the effective medium approximation which reproduces the percolation phenomenon well.