Collaborative Research: NSF/DOE Thermoelectrics Partnership: High Performance Thermoelectric Waste Heat Recovery System Based on Zintl Phase Materials with Embedded Nanoparticles

知识优势：基于丰富且无毒的锌相硅化镁合金将开发出新型热电材料。提出了一种在硅化镁合金基体中自然嵌入纳米颗粒的合成方法，提供了均匀的混合和最小的聚集。采用适当浓度和直径的纳米颗粒，可通过中长波长声子的散射降低导热系数。控制纳米颗粒相对于基体的异质结构能带偏移和势垒，热载流子的选择性散射可以提高功率因数。初步输运计算表明，在800K时可以达到ZT1.8。将对材料热电特性进行广泛的表征，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：本提案旨在提供可以对废热回收产生重大影响的基础知识。受益于合金材料外延生长纳米颗粒中电子和声子输运的精心优化，重点关注可扩展块体材料合成和火花等离子烧结，计划开发一种低成本，高性能的热电材料。具有化学和工程背景的共同pi之间的密切合作将为从事该项目的研究生提供一个很好的学习机会。学生将在国内和国际会议上展示他们的研究成果，并培养对材料开发复杂性的认识。在参与少数族裔外展项目、监督少数族裔学生和学员以及参与广泛的活动方面，这些pi有着悠久的历史。

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.