Collaborative Research: NSF/DOE Thermoelectric Partnership: High Performance thermoelectric waste heat recovery system based on Zintl phase materials with embedded nanoparticles

1048801 /1048799 Shakouri/Kauzlarich智力成果：将基于丰富且无毒的Zintl相硅化镁合金开发新型热电材料。提出了一种合成方法，该方法自然地在硅化镁合金基体内提供嵌入的纳米颗粒，从而提供具有最小聚集的均匀混合。通过使用适当浓度和直径的嵌入式纳米颗粒，热导率将通过中长波长声子的散射而降低。通过控制异质结能带偏移和纳米粒子相对于基体的势垒，可以通过热载流子的选择性散射来提高功率因数。初步的输运计算表明，在800 K下ZT1.8可以实现。材料热电性能的广泛表征将进行，结果将与NASA喷气推进实验室和BSST的合作者进行基准测试。更广泛的影响：该提案旨在提供对废热回收产生重大影响的基础知识。受益于在合金材料中外延生长的纳米颗粒中实现的电子和声子输运的仔细优化，并专注于可扩展的块体材料合成和放电等离子体烧结，该计划是开发低成本，高性能热电材料。具有化学和工程背景的合作PI之间的密切合作将为从事该项目的研究生提供很好的学习机会。学生将在国家和国际会议上展示他们的研究成果，并对材料开发的复杂性进行欣赏。PI有参与代表性不足的少数民族外展计划的历史，监督少数民族学生和学员，并参加广泛的活动。

1048801 / 1048799Shakouri / KauzlarichIntellectual Merit: Novel thermoelectric materials will be developed based on abundant and non-toxic Zintl phase magnesium silicide alloys. A synthesis method is proposed that naturally provides embedded nanoparticles within a magnesium silicide alloy matrix, providing uniform mixing with minimal aggregation. With the use of embedded nanoparticles of appropriate concentration and diameter, thermal conductivity will be reduced by scattering of mid-long-wavelength phonons. Controlling the heterostructure band offset and the potential barrier of nanoparticles with respect to the matrix, the power factor will be increased by selective scattering of hot carriers. Preliminary transport calculations show that ZT1.8 at 800K could be achieved. Extensive characterization of the material thermoelectric properties will be performed and the results will be benched marked with collaborators at NASA JPL and BSST.Broader Impact: This proposal seeks to provide fundamental knowledge which can have a major impact on waste heat recovery. Benefiting from the careful optimization of the electron and phonon transport achieved in eptiaxially grown nanoparticle in alloy material and focusing on scalable bulk material synthesis and spark plasma sintering, the plan is to develop a low cost, high performance thermoelectric material. The close collaboration between co-PIs with background in chemistry and engineering will provide a great learning opportunity for graduate students working on the project. Students will present their research at national and international meetings and will develop an appreciation for the complexity of materials development. The PIs have a history of participation in underrepresented minority outreach programs, supervising minority students and trainees, and participating in a broad array of activities.