在多元掺杂型CoSb3基方钴矿中引入纳米结构，获得纳米复合材料，是进一步提高该体系电声输运性能的重要途径。本项目拟采用高温高压方法制备一种新型结构的CoSb3基热电材料，即多元系CoSb3/CNTs复合材料。通过元素的多元填充协同多元置换，调查掺杂（填充+置换）元素种类和掺杂比例，建立掺杂元素及掺杂量与合成压力之间的关系，进而探明掺杂元素和压力对体系组分、晶体结构、能带结构、载流子传输特性、声子传输特性的调节规律。通过非原位引入碳纳米管得到多元系CoSb3/CNTs复合物，研究纳米第二相与界面对声子及载流子的散射和降低热导率的机理。揭示高压下制备复合材料的晶体结构、电子结构、微观组织、掺杂元素、掺杂方式和掺杂匹配度等影响材料热电性能的物理机制。开展本项目研究对阐明纳米复合材料的电声传输机制等具有重要的理论意义和应用价值。

It is an important way to improve the performance of the electron-phonon transport by introducing nano-structure into the multi-element dope-CoSb3 system to obtain the nano-composite materials. This project is to prepare a new structure of CoSb3-based thermoelectric materialsvia high pressure and high temperature (HPHT) method, namely multi-element doped CoSb3 /CNTs composite materials. It focus on establishing the relationships between the types and ratio of the doping elements and the synthesis pressure by investigating the collaborative effect of multi-filling and multi-substituting, and then we can find out the regulation rules of the doping elements and pressure for system composition, crystal structure, band structure, carrier transmission characteristics and phonon transmission characteristics. Carbon nanotubes (CNTs) are introduced into multicomponent CoSb3/CNTs composites, and the mechanism leading to thermal conductivity reduction of phonons and carriers scattered bythe nano-scale second phase and grain boundaries are studied. The physical mechanism of crystal structure, electron structure, microstructure, doping elements, doping method and doping matching degree of the composite materials synthesized by HPHT are revealed. The research of this project has important theoretical significance and application value to elucidate the electron-phonon transport mechanism of nano-composite materials.