Collaborative Research: Hybrid Organic-Inorganic Thermoelectric Materials

建议1400246合作研究：有机-无机混合热电材料摘要：热电材料是一种可以将热能直接转化为电能的材料。热电材料的性能是用称为ZT的“品质系数”来衡量的。关于提高热电材料的品质因数，人们已经进行了大量的研究，但进展缓慢，到目前为止，所研究的热电材料要么是制造成本高，要么是稀土或有毒元素的使用，要么是力学性能差。有机热电材料(OTES)由于具有柔性、低成本、储量丰富等特点，近年来在低温(300K)，特别是制冷方面的应用引起了人们的广泛关注，并且已经有了低成本的制备方法。然而，最先进的OTES的ZT明显低于其无机同行的ZT。事实上，即使在无机材料中，低温热电器件的候选者也很少。对于无机热电材料，提高ZT的限制因素是电子迁移率。这项工作将通过解决迁移率提高方面的挑战来制造高ZT热电材料。这将通过将两类材料(有机和无机)结合起来，使用一种将高迁移率的无机纳米线嵌入有机化合物的制造方案来实现。研究人员是一个多学科团队，在热电领域具有互补的专业知识和共同的兴趣。因此，参与该项目的研究生和本科生将很大程度上受益于这项工作的多学科性质。这项工作是将新的掺杂方案(3D调制掺杂和场效应掺杂)应用于有机-无机杂化材料，并模拟、设计、制备和表征一类新的低温热电纳米复合材料。两相材料以有机相(如共轭聚合物或有机分子)为电子源，以无机半导体相(如硅纳米线)为电子传输通道，具有较高的迁移率。关键是利用调制掺杂方案有利于载流子从载流子源(如共轭聚合物)向高迁移率的无机半导体相(无机纳米线)的转移，并优化载流子浓度以设计高Z杂化热电材料。我们将模拟、合成和优化一大类与共轭聚合物(例如，化学修饰的PEDOT和低禁带聚合物)和有机分子(附着在CF3取代的苯乙烯分子等分子上的特殊带电化学物种)相结合的半导体纳米结构(例如，硅、镉、铋和铅纳米线和孔结构)，以确定具有潜在高ZT的新型杂化材料。

Proposal 1400246Collaborative Research: Hybrid organic-inorganic thermoelectric materialsAbstract: Thermoelectric materials are materials which can be used to convert thermal energy directly to electricity. The performance of a thermoelectric material is measured by the "figure of merit", termed ZT. There has been much research into increasing thermoelectric materials, figure of merit, however, progress in this area has been slow and most of the researched thermoelectric materials up to now are suffering from either high fabrication cost, usage of rare earth or toxic elements, or poor mechanical properties. Organic thermoelectric materials (OTEs) have recently attracted attention for low temperature applications ( 300K), especially cooling purposes, as they are flexible, low-cost and abundant, and low-cost fabrication methods for synthesizing them exist. However, the ZT of the state-of-the-art OTEs is significantly lower than the ZT of their inorganic counterparts. In fact, there are only few candidates for low temperature thermoelectric devices even among inorganic materials. In the case of inorganic thermoelectric materials, the limiting factor in improving ZT is the electron mobility. This work will allow for the fabrication of high-ZT thermoelectric materials by addressing the challenges in mobility enhancement. This will be done by combining the two classes of materials (organic and inorganic), using a fabrication scheme in which high-mobility inorganic nanowires are embedded inside organic compounds. The researchers are a multidisciplinary team with complementary expertise and with common interest in the thermoelectric field. Graduate and Undergraduate Students involved in this project therefore will benefit largely from the multidisciplinary nature of the work.This work is applying new doping schemes (3D modulation-doping and field-effect doping) to hybrid organic-inorganic materials and to simulate, design, fabricate and characterize a new class of low temperature thermoelectric nanocomposites. The two-phase material uses the organic phase (e.g. conjugated-polymer or organic molecules) as a source of electrons and the inorganic semiconducting phase (e.g. Si nanowires) as the electron transport channel with high mobility. The key is to use the modulation-doping scheme to favor carrier transfer from the source of carriers (e.g. conjugated-polymer) to the high mobility inorganic semiconducting phase (inorganic nanowires) and optimize the carrier concentration to design a high Z hybrid thermoelectric material. A large class of semiconducting nanostructures (e.g. Si, CdTe, Bi, and PbTe nanowires and holely structures) combined with conjugated polymers (e.g., chemically-modified PEDOT and low bandgap polymers) and organic molecules (specifically charged chemical species attached to molecules such as CF3- substituted styrene molecules) will be simulated, synthesized and optimized to identify new hybrid materials with a potentially high ZT.