组合材料学方法设计和优化新热电化合物的研究

Based on a process of synthesizing a so-called combinatorial library, namely, a great number of samples obtained in parallel with compositional or structural variations, followed by a high throughput characterization of these samples, combinatorial materials science can efficiently obtain composition-structure-properties correlations and screen for the possible candidates in the combinatorial library, therefore to discovery new materials. Multinary chalcogenides with diamond-like structure have been found as promising thermoelectric materials. To develop and identify new thermoelectric compounds with high performance in the family of multinary chalcogenides, this proposal will adopt the research principles of combinatorial materials science. While pointing out the questions that exist in the earlier researches of thermoelectric materials by using combinatorial materials science principles, we propose to develop a new technique to prepare the combinatorial library of thermoelectric materials based on the diffusion multiple method, to set up an unique high-throughput measurement tool which can acquire all the three thermoelectric parameters rapidly, in-situ and at the same time, with the goal to uncover and quickly establish the composition-phase-microstructure-thermoelectric properties relationships for the multinary chalcogenides systems, and finally to discover and optimize the possible novel thermoelectric compounds in the family of multinary chalcogenides. This research will help broaden the application field of combinatorial materials science and principle, promote the development of the related theories and research techniques; and it also provides a new approach to explore and optimize the new thermoelectric compounds rapidly, efficiently and with a lower cost, which is very important for boosting the development of new thermoelectric materials and application of the thermoelectric power generation technique.

组合材料学通过一次制备大量的不同组成或结构的样品库，然后对样品库进行高通量表征，高效的获得样品库组成-结构-性能之间的关系以及对样品库筛选进而发现新材料。具有类金刚石结构的多元硫族化合物作为热电材料具有很大的潜力，为发展和寻找多元硫族化合物中可能存在的性能优异的新热电化合物，本项目采用组合材料学方法，针对目前组合材料学方法在热电材料研究中存在的问题，发展基于多元扩散偶技术的热电材料组合材料库制备新技术，建立能对热电材料三个参数快速、原位和同时测试的高通量表征新技术，揭示和快速建立多元硫族化合物组成-物相-微观结构-热电性能之间的关系，发现和优化多元硫族化合物中可能存在的新热电化合物体系。本研究将拓展组合材料学研究方法的应用领域，促进组合材料学理论及技术的发展，为新热电化合物体系的探索和优化提供一种快速、高效和低成本的新途径，对加快新热电材料的开发和热电发电技术的应用具有重要意义。

组合材料学通过一次制备大量的不同组成或结构的样品库，然后对样品库进行高通量表征，高效的获得样品库组成-结构-性能之间的关系以及对样品库筛选进而发现新材料。具有类金刚石结构的多元硫族化合物作为热电材料具有很大的潜力，为发展和寻找多元硫族化合物中可能存在的性能优异的新热电化合物，本项目采用组合材料学方法，建立了基于放电等离子烧结和热锻退火的高通量制备技术，建立了基于扫描Seebeck探针显微镜的扩散偶样品库的电导率和Seebeck系数的高通量表征技术，以Ge-Sb-Te基化合物体系为研究对象，探究了熔融法和等离子体活化烧结法等制备方法，制备出了组成和结构丰富多样的块体热电材料组合样品库，进而通过对组合样品库中不同微区化学组成、晶体结构和热电性能的分析，揭示了材料的组成-结构-性能之间的关系，实现了筛选出热电性能优异的Ge-Sb-Te基新化合物的目的。在以上研究的基础上确定了Ge33.1Sb13.7Te53.2及其附近组成为可能包含具有优异热电性能的化合物，通过块体材料验证Ge38Sb10.3Te51.7在所制备样品中表现出最优异的热电性能，在773 K时ZT取得最大值1.35。本研究拓展了组合材料学研究方法的应用领域，促进组合材料学理论及技术的发展，为新热电化合物体系的探索和优化提供一种快速、高效和低成本的新途径，对加快新热电材料的开发和热电发电技术的应用具有重要意义。