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

该项目的主要目的是完成描述纳米结构材料热电特性的多尺度模型的开发。其目的是从微观到宏观的尺度上全面了解样品的结构、电子和振动特性与其宏观输运系数、导热系数κ、电导率σ和塞贝克系数s之间的关系。除了宏观测量外，还采用不同的无创扫描探针技术在微观尺度上测量电子和振动状态以及输运系数。理论重点在于弥合弹道输运和扩散输运之间的差距。该理论模型及其局限性将通过研究一系列物理问题来严格检验，这些物理问题涉及纳米结构材料的主要问题，即不同长度尺度上的声子散射、原子在界面上的扩散和渗透效应。为了测试模型，专门设计的基于ZnO-ZnS半导体系统的横向纳米结构样品将以两种类型的配置I和II制造，允许一个人确定所有的横向热电输运系数。

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.