基于能隙调控的BiTe近室温热电性能优化及机理的研究

现代社会环境保护意识越来越强，化学制冷剂的使用会对环境造成危害。环境友好型近室温热电材料可以用电制冷，能减少化学制冷剂对环境的影响。本项目聚焦拥有商用室温热电材料Bi2Te3的[Bi2]m[Bi2Q3]n家族，以该家族中BiTe化合物为研究对象，基于费米能级附近能带的轨道组成和成键分析，从轨道能量的角度选择可降低能隙的阳离子，结合热电性能理论预测筛选出可提高材料近室温性能的掺杂剂，通过实验验证理论计算结果，从而实现材料近室温热电性能的提升。基于掺杂模型的能带结构和声子谱，分析掺杂剂导致的能带轨道成分以及原子振动变化的原因，从而研究材料电、热输运性能变化的机理，发现提高BiTe以及该家族其他材料近室温热电性能的方法。本项目旨在将理论与实验相结合，探索能带轨道组成与电、热输运性能的关系，拓展近室温热电材料的边界，从而为近室温热电材料更广泛的应用提供理论支撑和实验基础。

In modern society, the awareness of environmental protection is becoming stronger, the use of chemical refrigerants will cause harm to the environment. Environment-friendly near room temperature thermoelectric materials can use electricity to cooling, which can reduce the impact of chemical refrigerants on the environment. This project focus on [Bi2]m[Bi2Q3]n family with commercial thermoelectric material Bi2Te3, the BiTe in the family as the research object, based on analysis of orbit and bonding of band near Fermi energy, from the view of the orbitals energy, select cation dopants to reduce the energy gap. Combining with the theory of thermoelectric performance prediction filter dopant that can improve the properties of materials near room temperature, through experiment to verify the results of theoretical, to increase near room temperature thermoelectric performance of materials. Based on the band structure and phonon spectrum of the doping model, analyze the changes of band structure orbitals composition and atomic vibration, to study the mechanism of the change of electrical and thermal transport properties of the materials, and will find a method to improve the near room temperature thermoelectric properties of BiTe and other materials of family. This project aims to combine theory with experiment, explore the relationship between band structure orbits composition and electrical, thermal transport performance, and expand the boundary of near room temperature thermoelectric materials, to provide theoretical support and experimental basis for the wider application of near room temperature thermoelectric materials.