Hybrid Thermoelectric Materials Based on Porous Silicon: Linking Macroscopic Transport Phenomena to Microscopic Structure and Elementary Excitations

该项目的目标是开发和理解基于纳米结构硅和功能化聚合物的新型杂化热电材料。简而言之，在由多孔硅作为主衬底和导电聚合物（如PEDOT）作为客体分子组成的混合系统中，应该克服体硅众所周知的糟糕热电性能。在这里，结构主体保证了至少非常低的热导率，这是一种优秀的热电材料的先决条件，而电性能可以通过适当选择主体分子来有利地调节。我们建议通过x射线和中子散射实验，将合成的杂化样品的宏观热电特性与结构和动力学研究结合起来。目标是基本理解宏观量，如电导率，导热系数和塞贝克系数如何在微观层面上与电子能带结构和声子色散相关。它将被全面调查，主人和客人的属性如何与混合系统的属性相关，以及如何协同效应可能出现。理想情况下，这项研究为更有效的热电材料的新设计策略铺平了道路。

The project objective is to develop and understand novel hybrid thermoelectric materials based on nanostructured silicon and functionalized polymers. In a nutshell, the notoriously bad thermoelectric performance of bulk silicon shall be overcome in hybrid systems consisting of porous silicon as host substrate and conductive polymers like PEDOT as guest molecules. Here the structured host guarantees at least very low thermal conductivity as prerequisite for an excellent thermoelectric material, whereas electrical properties can be favorably tuned by proper selection of the host molecules. We propose to combine a full macroscopic, thermoelectric characterization of synthesized hybrid samples with structural and dynamical studies by means of x-ray and neutron scattering experiments. Goal is a fundamental understanding of how macroscopic quantities like electrical conductivity, thermal conductivity and Seebeck coefficient relate to electronic band structure and phonon dispersion on a microscopic level. It will be comprehensively investigated, how the properties of host and guest relate to the properties of the hybrid systems and how synergy effects might arise. Ideally, this studies pave the route towards novel design strategies for more efficient thermoelectric materials.