Collaborative Research: Thermoelectric Devices Based on Laser Sintering of Doped SiGe Nanoparticles

合作研究：基于激光烧结掺杂SiGe纳米粒子的热电器件

• 批准号: 1408443
• 负责人: Mool Gupta
• 金额: $ 25.06万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1408443&HistoricalAwards=false
• 关键词: Collaborative; Research; Thermoelectric; Devices; Based

A large amount of energy is wasted through heat dissipation in many industrial processes and consumer systems. This waste of energy occurs as many of the current systems such as refrigerators, automobiles, and industrial process are fundamentally very inefficient and power is wasted as heat. Some of this waste heat could be utilized with low-cost recovery technologies. However, current waste heat conversion devices are very inefficient and are relatively expensive. Hence, research needs to be carried out to find low cost and more efficient solutions for waste heat recovery. The proposed research will investigate a new thermoelectric (thermal-to-electric energy conversion) process for developing efficient waste heat recovery at low cost. The research will also train future scientists and engineers in the energy sector. The principal investigator and co-principal investigator will involve teachers and students in the project and will display materials at the local Science Museum and library as part of outreach and educational activities. The growth of alternative energy technologies will have an important impact on society to meet its energy needs and will lower the nation's dependence on foreign oil thus improving the nation's energy security.Significant progress has been made in thermoelectric power conversion devices with efficiencies reaching over 10%. To realize the commercial potential of thermoelectric devices, further improvements in efficiency, long-term stability at high temperatures and lower cost of fabrication must be realized. A world-wide research effort is being carried out to realize the above goals. Correspondingly, this proposal consists of a multidisciplinary team of a faculty member from the University of Minnesota (Prof. Kortshagen) with research expertise in novel gas phase synthesis of nanoparticles and a faculty member from the University of Virginia (Prof. Gupta) with research expertise in laser processing and device physics. The research plan is to provide understanding of nanograined thermoelectric materials and to achieve further enhancement in efficiency, long-term stability and reduced fabrication costs. The hypothesis of the research is that nanograined materials can enhance the overall thermoelectric device efficiency by reduction of thermal conductivity due to enormous interfacial area causing enhanced phonon scattering and an increase of Seebeck coefficient due to filtering of electron energy producing a higher voltage. Another hypothesis is that nearly fully-dense films and bulk materials can be realized by pulsed laser sintering of nanoparticles to avoid major grain growth by nanosecond heating and cooling rates. The realization of the goals will be achieved through the following tasks: (1) vapor phase synthesis of SiGe nanoparticles of 20 nm in size, (2) p- and n- type doping of SiGe nanoparticles during vapor phase synthesis, (3) nanosecond pulsed laser sintering of vapor phase synthesized nanoparticles of SiGe to achieve close to theoretical density, (4) fabrication of thermoelectric devices and evaluation of high-temperature performance up to 1000 °C, and (5) enhancement of research through collaboration with DOE funded thermoelectric materials and device laboratory at Oak Ridge National Laboratory for fundamental understanding of material and device properties at very high temperatures using state of the art high-temperature characterization facility for crystal structures, electrical and thermal properties.

在许多工业过程和消费系统中，大量的能源通过散热而被浪费，这种能源浪费的发生是因为许多当前的系统（例如冰箱、汽车和工业过程）从根本上来说效率非常低，并且电力被浪费为热量。这些废热可以通过低成本回收技术来利用，但是目前的废热转换装置效率非常低，因此需要进行研究以找到低成本和更有效的废热回收解决方案。拟议的研究将调查一种新的该研究还将培训能源领域未来的科学家和工程师。项目并将在当地科学博物馆和图书馆展示材料，作为推广和教育活动的一部分。替代能源技术的发展将对社会满足其能源需求产生重要影响，并将降低国家对外国石油的依赖，从而改善能源状况。国家能源安全意义重大热电转换器件已取得进展，效率达到 10% 以上。为了实现热电器件的商业潜力，必须进一步提高效率、高温下的长期稳定性和降低制造成本。相应地，该提案由来自明尼苏达大学的一名在纳米颗粒新型气相合成方面具有研究专长的教职人员（Kortshagen 教授）和一名教职人员组成的多学科团队正在开展研究工作。来自弗吉尼亚大学的 Gupta 教授拥有激光加工和器件物理学方面的研究专业知识，该研究计划旨在提供对纳米晶热电材料的理解，并实现进一步提高效率、长期稳定性和降低制造成本的假设。该研究的主要内容是，纳米颗粒材料可以通过降低热导率来提高整体热电装置的效率，因为巨大的界面面积会导致声子散射增强，并且由于过滤电子能量产生更高的电压而增加塞贝克系数。通过脉冲激光烧结纳米颗粒可以实现全致密薄膜和块体材料，以避免纳秒加热和冷却速率导致的主要晶粒生长。该目标的实现将通过以下任务来实现：（1）SiGe纳米颗粒的气相合成。尺寸为 20 nm，(2) 在气相合成过程中对 SiGe 纳米颗粒进行 p 型和 n 型掺杂，(3) 气相合成纳米颗粒的纳秒脉冲激光烧结SiGe 实现接近理论密度，(4) 制造热电器件并评估高达 1000 °C 的高温性能，以及 (5) 通过与美国能源部资助的橡树岭国家实验室热电材料和器件实验室合作加强研究使用最先进的晶体结构、电学和热学特性高温表征设备，对极高温度下的材料和器件特性进行基本了解。