I-III-VI2型类金刚石化合物的能带结构调控和热电性能研究

项目名称： I-III-VI2型类金刚石化合物的能带结构调控和热电性能研究

项目编号： No.51302300

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 刘睿恒

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 25万元

中文摘要： 类金刚石化合物作为一类新兴的中温区热电材料有望用于废热回收利用等领域,其中I-III-VI2型材料因高的结构对称性和载流子迁移率，比其他类金刚石材料更具优势，但其电输运性能仍远低于传统的热电材料。由于该类化合物较高的结构对称性为能带结构的调控提供了很好的平台，从而可以通过能带调控提升赛贝克系数以及优化电输运性能，因此本项目拟通过第一性原理计算和实验相结合的方法，研究揭示其晶体结构参数对能带结构的影响；在此基础上设计采用固溶的方式对其能带结构进行调控，增大其价带顶处能带的简并度，并选取恰当的离子掺杂对其载流子浓度进行优化，改善其电学性能；最终实现电性能和热导率的协同调控，获得ZT>1.3可与典型笼状结构方钴矿相当的I-III-VI2型类金刚石热电材料。本项目对深入理解类金刚石化合物能带调控机制，研发具有高性能的类金刚石化合物具有重要意义。

中文关键词： 热电材料；类金刚石化合物；高通量筛选；赝立方结构；

英文摘要： As a new class of thermoelectric materials,Diamond-like compounds are expected for waste heat recovery and other fields. I-III-VI2 type compounds have great advantage than other diamond-like compounds because of high mobility and high crystal symmetry. However, the electrical property is lower than the traditional thermoelectric materials. Since the exist of tetrahedron structure provides an optimization platform for band structure and electrical proformance, this project intends to investigate the relationship between crystal structure and band structure of I-III-VI2 compounds by a combination of first-principles calculations and experimental method, and then reveal the fundamental mechanism for band evoluation and enegineering.Then suitable doping or solid solution approaches would be applied to improve the density of state and then optimize the electrical transport properties of the I-III-VI2 type materials. Through preparing component controllable doping or solid solution samples,we try to study the doping and solution effect on the carrier concentration and thermal conductivity, reveals the suitable doping elements, doping position and the optimized carrier concentration , finally obtain novel high-performance I-III-VI2 type thermoelectric materials with ZT> 1.3.This project is highly meaningful to deeply

英文关键词： thermoelectric；diamond-like compound；high-throughput screening；quasi-cubic；