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：热电材料是可以将热能直接转化为电能的材料。热电材料的性能是通过“优点值”（称为ZT）来衡量的。近年来，人们对增温热电材料进行了大量的研究，但研究进展缓慢，目前所研究的热电材料大多存在制造成本高、使用稀土或有毒元素、力学性能差等问题。近年来，有机热电材料（OTEs）因其柔性、低成本和储量丰富，以及存在低成本的制备方法而在低温（300K），特别是冷却方面的应用受到了人们的关注。然而，最先进的OTEs的ZT明显低于无机OTEs的ZT。事实上，即使在无机材料中，低温热电器件的候选材料也很少。对于无机热电材料，提高ZT的限制因素是电子迁移率。通过解决流动性增强方面的挑战，这项工作将允许制造高zt热电材料。这将通过结合两类材料（有机和无机）来实现，使用一种制造方案，将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从这项工作的多学科性质中受益匪浅。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（如共轭聚合物或有机分子）作为电子源，无机半导体相（如硅纳米线）作为具有高迁移率的电子传递通道。关键是利用调制掺杂方案促进载流子从载流子源（如共轭聚合物）转移到高迁移率的无机半导体相（无机纳米线），并优化载流子浓度以设计高Z杂化热电材料。一大批半导体纳米结构（如Si、CdTe、Bi和PbTe纳米线和全孔结构）与共轭聚合物（如化学修饰的PEDOT和低带隙聚合物）和有机分子（附着在分子上的特定带电化学物质，如CF3取代的苯乙烯分子）相结合，将被模拟、合成和优化，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.