NSF/DOE Thermoelectrics Partnership: INORGANIC-ORGANIC HYBRID THERMOELECTRICS

NSF/DOE 热电合作伙伴关系：无机-有机混合热电学

• 批准号: 1048702
• 负责人: Sreeram Vaddiraju
• 金额: $ 42.7万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1048702&HistoricalAwards=false
• 关键词: NSF; DOE; Thermoelectrics; Partnership; INORGANIC

1048702VaddirajuIntellectual Merit: The proposal uses solid-state thermoelectric modules to convert automobile waste heat directly into clean electricity without contributing additional greenhouse gas emissions. Suitable thermoelectric devices require: 1) high conversion efficiencies, 2) optimized form factor, 3) high stability, and 4) tunability for optimized system design. For widespread use of thermoelectric modules in automobiles, a zT3 is needed, which is not possible with the current state-of-the-art devices. Recent theoretical predictions indicate that one-dimensional nanostructures (nanowires) are useful for the fabrication of highly efficient thermoelectric modules. Fabrication of thermoelectric devices and modules with zT3 performance requires answering two overarching questions: Q1) what are the sizes and chemical compositions of inorganic nanowires required for achieving zT3 performance? Q2) how can these nanowires be integrated on a large-scale into thermoelectric devices and modules? This proposal?s hypothesis is that thermoelectric devices with zT3 can be fabricated through an ?out-of-the-box? approach that utilizes organic and inorganic materials in unison, performed through homogeneous ?molecular wiring? of inorganic nanowires either to each other or though heterogeneous ?wiring? to organic semiconductor thin films. These two approaches are expected to solve the elusive problem of large-scale integration of nanomaterials while also providing the necessary flexibility for judicious selection of both the chemical components for high thermoelectric performance. The final goal of demonstrating zT3 performance in large ( 1inch2) inorganic-organic hybrid TE devices will be realized by: 1) Using well-known chemical vapor deposition techniques, modified to this application, to synthesize both inorganic nanowires and organic thin films, followed by assembling them using ?molecular wiring? into cells of various sizes ranging from a few nm2 to a few cm2. 2) Systematically studying the effect of inorganic nanowire size and organic conducting polymer thin film chemistry and thickness on their individual thermoelectric performance, and also on their performance when used in unison as ?molecular wired? inorganic-organic hybrids.A second advantage offered by the proposed ?molecular wired? assemblies is enhanced stability against air and moisture-assisted degradation and also against high temperature degradation. This is owed to the saturation of all dangling bonds in the hybrids, leaving no room for both oxygen/moisture adsorption and reaction. This complete saturation of dangling bonds is also expected to make the hybrids stable at very high temperatures. A large temperature difference, as high as 800oC, is available for electricity generation in automobiles. Hence, systematic investigation of the thermoelectric performance of the hybrids over a wide temperature range of 25-800oC will be performed to evaluate the temperature range over which stable zT3 performance could be realized in them.Finally, assembling individual TE devices into modules requires a metal that exhibits low resistance to charge transfer when brought into contact with the TE cells. Hence, the last aspect of the proposed study is to determine the type of the metal required for assembling individual TE devices into TE modules without lowering their performance.Systematic studies of the contact resistance of metal-hybrid junctions will be performed by varying the material of the metal in contact with the hybrids (using transfer length method). The type of the metal required for assembling individual TE devices into modules exhibiting zT3 performance will be deduced.Broader Impact: The educational impact of the proposed work will be the training of high school, undergraduate and graduate students through various avenues. 1) The PI, in collaboration with Mr. Berkan kaya, Assistant Principal at Harmony Science Academy, proposes to train high school students from Harmony Science Academy in Houston, TX and teach them techniques of nanomaterials synthesis and characterization. Small projects aimed at fabrication of energy conversion devices will be designed and the results of their work will be presented at various science fairs and competitions, such as ?International Sustainable World (Engineering, Environment, Energy) (www.isweeep.org). 2) The PI is also a volunteer for the NASA?s Motivating Undergraduates in Science and Technology (http://mustmentor.org) project. Through this avenue, the PI proposes to recruit undergraduate students and train them on the techniques for the fabrication of thermoelectrics and further motivate them to pursue graduate education. 3) Training of graduate students will include development of a new class useful for students across many disciplines. This class tentatively scheduled to be offered in spring 2011 is entitled ?Nanomaterials for Energy Conversion?.

1048702 Vaddiraju的智力优势：该提案使用固态热电模块将汽车废热直接转化为清洁电力，而不会产生额外的温室气体排放。合适的热电器件需要：1）高转换效率，2）优化的形状因子，3）高稳定性，以及4）用于优化系统设计的可调谐性。为了在汽车中广泛使用热电模块，需要zT 3，这对于当前最先进的设备是不可能的。最近的理论预测表明，一维纳米结构（纳米线）是有用的高效热电模块的制造。制造具有zT 3性能的热电器件和模块需要回答两个首要问题：Q1）实现zT 3性能所需的无机纳米线的尺寸和化学成分是什么？ Q2）如何将这些纳米线大规模集成到热电设备和模块中？ 这个提议？的假设是，热电器件与zT 3可以通过一个？开箱即用的方法，利用有机和无机材料一致，通过均匀的？分子线路无机纳米线之间的相互作用还是异质的？接线？涉及有机半导体薄膜。这两种方法有望解决纳米材料大规模集成的难以捉摸的问题，同时也为明智地选择高热电性能的化学成分提供了必要的灵活性。证明zT 3在大（1英寸2）的无机-有机混合TE设备的性能的最终目标将实现：1）使用众所周知的化学气相沉积技术，修改本申请，合成无机纳米线和有机薄膜，然后组装它们使用？分子线路转化为从几nm 2到几cm 2的各种尺寸的细胞。 2)系统地研究无机纳米线的大小和有机导电聚合物薄膜的化学性质和厚度对它们各自的热电性能的影响，以及当它们作为？分子连线无机-有机混合物。分子连线在某些实施方案中，所述组合件增强了对空气和湿气辅助降解以及对高温降解的稳定性。这是由于杂化物中所有悬挂键的饱和，没有留下氧气/水分吸附和反应的空间。悬挂键的这种完全饱和也有望使杂化物在非常高的温度下稳定。在汽车上发电时，温差很大，高达800 ℃。因此，在25- 800 oC的宽温度范围内的混合动力车的热电性能的系统调查将进行评估的温度范围内，稳定的zT 3性能可以实现在them.Finally，组装成模块的单个TE设备需要一种金属，表现出低电阻电荷转移时，与TE电池接触。因此，建议的研究的最后一个方面是确定所需的金属的类型，用于将单个TE器件组装成TE模块，而不降低其性能。将通过改变与混合体接触的金属材料（使用转移长度法），对金属混合结的接触电阻进行系统的研究。将推导出将单个TE器件组装成具有zT 3性能的模块所需的金属类型。更广泛的影响：拟议工作的教育影响将是通过各种途径培训高中、本科和研究生。1)PI与Harmony Science Academy副校长Berkan卡亚先生合作，建议培训德克萨斯州休斯顿Harmony Science Academy的高中生，并教授他们纳米材料合成和表征技术。旨在制造能量转换装置的小型项目将被设计，他们的工作成果将在各种科学博览会和竞赛中展示，例如？国际可持续世界（工程、环境、能源）（www.isweeep.org）。2)私家侦探也是宇航局的志愿者？的激励科学和技术本科生（http：mustmentor.org）项目。通过这一途径，PI建议招收本科生，并对他们进行热电制造技术的培训，并进一步激励他们接受研究生教育。3)研究生的培训将包括开发一个对许多学科的学生有用的新课程。这门课暂定在2011年春季开设，名为？能量转换的纳米材料？