Thermoelectric properties of laterally nanostructured ZnO/ZnS thin films: theory and experiment

该项目的主要目标是完成描述纳米结构材料热电性能的多尺度模型的开发。其目的是从微观到宏观，全面了解样品的结构、电子和振动性质与宏观输运系数、导热系数κ、电导σ和塞贝克系数S之间的关系。实验工作的重点是在宏观测量之外，通过使用不同的非侵入性扫描探头技术，获得微观尺度上的结构、电子和振动状态以及输运系数的信息。理论上的重点在于弥合弹道运输和扩散运输之间的差距。通过研究一系列涉及纳米结构材料主要问题的物理问题，即不同长度尺度上的声子散射、界面上的原子扩散和渗流效应，将严格检验理论模型及其局限性。为了测试该模型，将制作两种配置I和II，以确定所有的横向热电传输系数。这些样品是基于氧化锌-硫化锌半导体系统的横向纳米结构。

The main aim of the project is to complete the development of a multiscale model for describing the thermoelectric properties of nanostructured materials. The intension is to obtain a full understanding from the microscopic to the macroscopic scale relating structural, electronic and vibrational properties of the samples to their macroscopic transport coefficients, thermal conductivity κ, electric conductivity σ, and Seebeck coefficient S. The emphasis of the experimental work lies on obtaining information about structure, electronic and vibrational states as well as transport coefficients on the microscopic scale by employing different non-invasive scanning probe techniques in addition to macroscopic measurements. The theoretical emphasis lies on bridging the gap between ballistic transport and diffusive transport. The theoretical model and its limitations will be tested rigorously by studying a series of physical problems addressing major issues of nanostructured materials, i.e. phonon scattering on different length scales, and atomic diffusion across interfaces, and percolation effects. For the testing of the model specifically designed laterally nanostructured samples based on the ZnO-ZnS semiconductor system will be fabricated in two types of configurations I and II allowing one to determine all lateral thermoelectric transport coefficients.