Enhancement of thermoelectric performance by synergistic effects from multiple dopings in complex oxides

0854467 Yu该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。研究和教育计划的中心是理解和操纵纳米结构复合氧化物材料中的能量传输现象，以及教育包括研究生，本科生和K-12学生在内的广泛的学生在能量转换过程方面。 研究包括：（1）通过受限氧化物结构的能量传输现象的调查;（2）在缺氧，杂质掺杂的纳米结构氧化物材料的热传输;和（3）多种掺杂剂对热电应用中电子和声子传输的影响。 此外，拟议的教育和推广计划将：（5）教育研究生和本科生，以及K-12学生和教师在纳米和微米尺度的热物理现象的能量转换;和（6）招募少数民族和妇女学习工程学科，并在研究生院注册。利用热电装置将废热转化为电的显著改进取决于热电材料的热导率的同时降低和电导率的提高。最近，一些研究人员提出，声子热导率的抑制在改善热电材料的性能方面非常有效，因为这会影响热输运，但通常对电子输运性质的影响很小。 然而，由于这些材料固有的低热导率，使用现有技术的碲化铋合金的当前努力没有提供足够的空间来获得热导率的大幅降低。 在这方面，探索过去没有被广泛考虑的材料，如复合氧化物，是及时和重要的。 这些氧化物的电和热传输特性可以使用各种方法改变，这为开发新的高性能热电材料提供了机会。 例如，同时使用属性调整方法可能会产生协同效应，这将大大提高热电性能。 从这项研究中获得的知识将推进对能量载体通过受限结构传输的基本理解，并将提供一种方法来定制许多不同材料的特性。 通过一系列实验和理论/计算计算，将获得对能量载体传输的理解，这些实验和理论/计算可以用作识别热电应用的其他有前途的复合氧化物的平台。 更广泛的影响：高效热电材料有潜力从废热中产生大量电力，同时减少温室气体排放。该研究将被整合到研究生课程以及核心本科课程，并将形成纳米科学相关课程和研讨会的演示文稿的基础，以及通过各种教育计划，包括工程丰富经验（E3）在得克萨斯州A M大学计划推广到K-12学生和教师。 对德克萨斯州少数民族和K-12学校的访问将鼓励妇女和代表性不足的群体在各种工程学科中攻读本科和研究生课程。

0854467YuThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The research and education plan centers on understanding and manipulating energy transport phenomena within nanostructured complex oxide materials, as well as educating a broad spectrum of students including graduate, undergraduate, and K-12 students in aspects of energy conversion processes. The research includes investigation of: (1) energy transport phenomena through confined oxide structures; (2) thermal transport in oxygen-deficient, impurity-doped nanostructured oxide materials; and (3) influence of multiple dopants on electron and phonon transport for thermoelectric applications. In addition, the proposed education and outreach program will: (5) educate graduate and undergraduate students, as well as K-12 students and teachers in nano- and micro-scale thermophysical phenomena for energy conversion; and (6) recruit minorities and women to study engineering disciplines and enroll in graduate schools.Intellectual Merit: Significant improvement in conversion of waste heat to electricity using thermoelectric devices hinges upon the simultaneous reduction of thermal conductivity and enhancement of electric conductivity of thermoelectric materials. Recently, several researchers have suggested that the suppression of phonon thermal conductivity is very effective in improving the performance of thermoelectric materials, as this influences thermal transport but often has a minimal influence on electronic transport properties. However, current efforts using state-of-the-art bismuth telluride alloys do not provide sufficient room to obtain a large reduction in thermal conductivity due to the intrinsically low thermal conductivity of these materials. In this regard, it is timely and important to explore materials that have not been considered extensively in the past, such as complex oxides. The electrical and thermal transport properties of these oxides can be altered using various methods, which provides an opportunity to develop new, high-performance thermoelectric materials. For example, the simultaneous use of property tuning methods might produce synergistic effects that will dramatically increase thermoelectric performance. The knowledge gained from this research will advance the fundamental understanding of energy carrier transport through confined structures and will provide a methodology to tailor the properties of many different materials. The understanding of energy-carrier transport will be obtained through a series of experiments and theoretical /computational calculations, that can be used as a platform to identify other promising complex oxides for thermoelectric applications. Broader Impacts: Highly efficient thermoelectric materials have the potential to generate large amounts of electric power from waste heat, while simultaneously reducing greenhouse gas emissions. The research will be integrated into a graduate course as well as core undergraduate courses, and will form the basis for presentations in nanoscience-related courses and seminars, as well as for outreach to K-12 students and teachers through various education programs including the Enrichment Experiences in Engineering (E3) program at Texas A&M University. Visits to minority and K-12 schools in Texas will encourage women and underrepresented groups to pursue undergraduate and graduate studies in various engineering disciplines.