Collaborative Research: Hybrid Organic-Inorganic Thermoelectric Materials

提案1400246合作研究：有机-无机杂化热电材料摘要：热电材料是一种可以将热能直接转化为电能的材料.热电材料的性能通过称为ZT的“品质因数”来测量。虽然人们对提高热电材料的品质因数进行了大量的研究，但是这一领域的进展一直很缓慢，迄今为止研究的大多数热电材料要么制造成本高，要么使用稀土或有毒元素，要么机械性能差。有机热电材料（OTE）最近在低温应用（300 K），特别是冷却目的方面引起了关注，因为它们是柔性的、低成本的和丰富的，并且存在用于合成它们的低成本制造方法。然而，最先进的OTE的ZT显著低于其无机对应物的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。在无机热电材料的情况下，提高ZT的限制因素是电子迁移率。这项工作将允许高ZT热电材料的制造，通过解决流动性增强的挑战。这将通过结合两类材料（有机和无机）来完成，使用一种制造方案，其中高迁移率的无机纳米线嵌入有机化合物中。研究人员是一个多学科的团队，具有互补的专业知识，并在热电领域的共同兴趣。因此，参与该项目的研究生和本科生将在很大程度上受益于这项多学科性质的工作。这项工作将新的掺杂方案（3D调制掺杂和场效应掺杂）应用于混合有机-无机材料，并模拟，设计，制造和表征一类新的低温热电纳米复合材料。两相材料使用有机相（例如共轭聚合物或有机分子）作为电子源，并且使用无机半导体相（例如Si纳米线）作为具有高迁移率的电子传输通道。关键是使用调制掺杂方案来促进载流子从载流子源（例如共轭聚合物）到高迁移率无机半导体相（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。一大类半导体纳米结构（例如Si、CdTe、Bi和PbTe纳米线和多孔结构）与共轭聚合物（例如，化学改性的PEDOT和低带隙聚合物）和有机分子（连接到分子如CF 3取代的苯乙烯分子上的特定带电化学物质）将被模拟、合成和优化，以识别具有潜在高ZT的新杂化材料。

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.