GOALI Collaborative Research: Intrinsically Minimal Thermal Conductivity in I-V-VI2 Thermoelectric Semiconductors

GOALI 合作研究：I-V-VI2 热电半导体本质上最小的导热率

• 批准号: 0754029
• 负责人: Donald Morelli
• 金额: --
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0754029&HistoricalAwards=false
• 关键词: GOALI; Collaborative; Research; Intrinsically; Minimal

CBET-0754029MorelliThe goal of this work is to lay the scientific groundwork to develop a new class of thermoelectric semiconductors based on I-V-VI2 compounds. This class of compounds possesses intrinsically the lowest lattice thermal conductivity possible in a crystalline material. Low lattice thermal conductivity is one of the prime factors in producing a high thermoelectric figure of merit; and ii) the PIs of this proposal have devised a method for preparing AgSbTe2 with very low carrier concentrations and high mobilities. The program is a GOALI with BSST as an industrial partner. Partnership with BSST, the world's largest user of thermoelectric materials, will ensure a rapid evaluation of the commercial potential of any new material produced. Intellectual MeritThis research will focus on rigorous experimental studies of the lattice and electronic properties of this class of semiconductors. The lattice thermal conductivity will be measured from 4 K to the melting point, with the Ag/Sb ordering as independent parameter. The data will be interpreted in terms of Umklapp and Normal phonon scattering processes, which will be derived without using adjustable relaxation times, and of the bond anharmonicity. Detailed band structure and Fermi surface information will be gleaned from Shubnikov-deHaas measurements. Preliminary first principle calculations show that AgSbTe2 may actually be a semimetal, and that its exact band structure is a function again of the amount of Ag/Sb ordering. The full galvanomagnetic, thermoelectric and thermomagnetic properties will be measured up to the melting point, and used to determine mobilities and electron scattering mechanisms. Broad ImpactEnhanced thermoelectric materials will enable an inexpensive method for converting solar thermal energy into electricity, and also will make possible the conversion of a fraction of the heat wasted by conventional heat engines, such as automotive power plants, into usable power. This is thus potentially transformative research that promises to reduce our reliance on fossil fuels, and to have a significant positive impact not only on the science and technology community, but on society in general. The partnership with BSST will ensure that the new thermoelectric materials are rapidly available for evaluation of their commercial potential. BSST will feed important information back to the research team about engineering criteria and the actual performance of the new materials in real electrical power generators. In the realm of education, this project will provide training for graduate students in a broad array of materials synthesis and characterization techniques. Additionally, results of the research will be incorporated into classes being developed by the PI?s in the areas of thermal transport and thermoelectricity. The significance of the broader issue of energy efficiency and usage that this research addresses will be integrated into the well established outreach programs at both institutions. Finally, the involvement of an industrial partner will give the students real-world experience into the engineering of transformative technological products and insight into the world of the energy industry.This project is jointly funded by the Thermal Transport Processes (TTP) Program, of the Chemical, Bioengineering, Environmental, and Transport Systems (CBET) Division, and by the Grant Opportunities for Academic Liaison with Industry (GOALI) Program, of the Industrial Innovation & Partnerships (IIP) Division, all within the Directorate for Engineering (ENG).

CBET-0754029Morelli 这项工作的目标是为开发基于 I-V-VI2 化合物的新型热电半导体奠定科学基础。 这类化合物本质上具有晶体材料中可能的最低晶格导热率。低晶格热导率是产生高热电品质因数的主要因素之一； ii) 该提案的 PI 设计了一种制备具有极低载流子浓度和高迁移率的 AgSbTe2 的方法。 该计划是 BSST 作为工业合作伙伴的 GOALI。 与全球最大的热电材料用户 BSST 的合作将确保对所生产的任何新材料的商业潜力进行快速评估。 智力价值这项研究将集中于对此类半导体的晶格和电子特性的严格实验研究。 晶格热导率将从 4 K 到熔点进行测量，以 Ag/Sb 排序作为独立参数。数据将根据 Umklapp 和法向声子散射过程进行解释，这些过程将在不使用可调节弛豫时间和键非谐性的情况下导出。 详细的能带结构和费米表面信息将从舒布尼科夫-德哈斯测量中收集。 初步的第一性原理计算表明，AgSbTe2 实际上可能是一种半金属，并且其确切的能带结构又是 Ag/Sb 有序量的函数。完整的电磁、热电和热磁特性将被测量到熔点，并用于确定迁移率和电子散射机制。 广泛影响增强型热电材料将提供一种廉价的方法将太阳热能转化为电能，并且还可以将传统热机（例如汽车发电厂）浪费的一小部分热量转化为可用电力。 因此，这是一项潜在的变革性研究，有望减少我们对化石燃料的依赖，不仅对科学技术界，而且对整个社会产生重大的积极影响。与 BSST 的合作将确保新型热电材料能够快速用于评估其商业潜力。 BSST 将向研究团队反馈有关工程标准和新材料在实际发电机中的实际性能的重要信息。在教育领域，该项目将为研究生提供广泛的材料合成和表征技术方面的培训。 此外，研究结果将被纳入热传输和热电领域 PI 正在开发的课程中。这项研究所解决的更广泛的能源效率和使用问题的重要性将被纳入两个机构完善的推广计划中。 最后，工业合作伙伴的参与将为学生提供变革性技术产品工程的实际经验，并深入了解能源行业的世界。该项目由化学、生物工程、环境和运输系统 (CBET) 部门的热传输过程 (TTP) 计划以及工业创新与合作伙伴关系的学术与工业联络机会 (GOALI) 计划共同资助 (IIP) 部门，均隶属于工程局 (ENG)。