纳米SiC弥散碲化铋基复合材料的热电性能及其增强机理研究

项目名称： 纳米SiC弥散碲化铋基复合材料的热电性能及其增强机理研究

项目编号： No.11474176

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 李敬锋

作者单位： 清华大学

项目金额： 105万元

中文摘要： 热电材料具有能够实现热能与电能相互直接转换的功能，相关研究日益受到多个学科的关注。在热电化合物基体中引入纳米尺度第二相，形成纳米复合结构成为提高热电性能优值（ZT值）的有效途径。在利用纳米弥散相的声子散射增强效应降低材料热导率的基础上，如何利用纳米复合结构实现Seebeck系数与电导率的相对独立调控，从而显著提高功率因子成为目前热电材料研究的重要方向。本项目拟围绕可能存在能量过滤效应的纳米SiC弥散碲化铋基复合材料，结合理论分析和实验重点研究纳米弥散相含量与大小以及界面结构对复合材料的Seebeck系数、电导率、热导率的影响规律，理清能量过滤效应在同型与异型纳米复合热电材料中的作用机制，勾画出更清晰的纳米复合结构能量过滤效应物理图像，为研发高性能纳米复合热电材料提供指导。

中文关键词： 热电材料；电输运；热电性能

英文摘要： Thermoelectric materials that enable direct conversion between thermal and electrical energy have received increasing attention from various disciplines. Creating a composite structure by incoporating nanophases into a thermoelectric compound matrix is an effective approach to enhance thermoelectric figure of meirt (ZT), due to reduced thermal conductivity through enhancing phonon scattering. Moreover, on such a basis, increasing power factor is becoming more and more important by decoupling Seebeck coefficients and electrical conductivity, which may be possible in the nanostructured composites. This project will be focused on nano-SiC-dispersed Bi2Te3-based composites, in which the energy filtering effect may exist, with an empahsis on the influence of the volume fraction and size of nanodispersions and interface nanostructure on Seebeck coefficient and electrical conductivity as well as thermal conductivity. We are also planning to investigate how energy filtering effect works in thermoelectric nanocomposites containing the same or different type semiconducting dispersions, so that a deeper understanding of its physical fundamentals in nanocomposite structures can be achieved. The eventual purpose of this project to provide more guidances for thermoelectric research.

英文关键词： thermoelectrics;electronic transport;thermoelectric property