Nanoporous Silicon: Probing Dimensionally Constrained Deformation in Non-Metals

这项工作的研究目标是了解纳米多孔硅的机械行为和结构稳定性是如何受到小变形体积和大表面积体积比的综合影响的。硅具有广泛的技术重要性和广泛的当前应用，将作为纳米结构非金属系统的模型材料。最近，一些研究小组报道了纳米硅结构在低于临界尺寸时表现出韧性变形。受这些结果的启发，本项目将研究纳米多孔硅的机械行为，其韧带结构由精细硅纳米线的互连网络组成。该研究方法结合了计算和实验方法，并利用了肯塔基州大学和卡尔斯鲁厄理工学院之间正在进行的合作。拟议的研究专门针对结构和机械表征纳米多孔硅，并模拟和建模纳米多孔硅变形。研究人员将利用在列克星敦（肯塔基州）和卡尔斯鲁厄（德国）建立的一系列薄膜和小规模测试技术以及原子计算模型来实现这些目标。综合结果将用于阐明纳米多孔硅的结构稳定性、力学性能和变形机制，特别是纳米韧带结构对硅变形的尺寸约束作用。本研究项目的成功将有助于更广泛地将纳米结构非金属应用于技术应用，以及纳米结构硅在工业相关工程解决方案中的部署。拟议的研究建立了相关设备级工程工作所需的基本理解，以开发下一代光电子器件，光学传感器，电池阳极，柔性电子器件或纳米级发光二极管。此外，德国卡尔斯鲁厄大学的合作将为美国学生提供在世界一流的国际研究环境中的实践实验室经验，为德国学生提供在美国生活和进行研究的机会，并为所有学生提供与外国同行在以科学为重点的文化交流中合作的机会。

The research objective of this work is to understand how the mechanical behavior and structural stability of nanoporous silicon are influenced by the combined effects of small deformation volume and large surface-area-to-volume ratio. Silicon, with broad technological importance and wide current application, will serve as a model material for nanostructured non-metallic systems. Recently, a number of research groups have reported that nanoscale silicon structures exhibit ductile deformation below a critical size. Motivated by these results, this project will investigate the mechanical behavior of nanoporous silicon whose ligament structure consists of an interconnected network of fine silicon nanowires. The research approach combines computational and experimental methodologies and leverages an ongoing collaboration between the University of Kentucky and the Karlsruhe Institute of Technology. The proposed research specifically aims to structurally and mechanically characterize nanoporous silicon, and to simulate and model nanoporous silicon deformation. The investigators will utilize a battery of thin film and small-scale test techniques that have been established in Lexington (Kentucky) and Karlsruhe (Germany) as well as atomistic computational models to realize these aims. Combined results will then be leveraged to elucidate the structural stability, mechanical properties and deformation mechanisms of nanoporous silicon, particularly with respect to the role of dimensional constraints placed on silicon deformation by the nanoscale ligament structure.Success in this research project will benefit efforts to more broadly incorporate nanostructured non-metals in technological applications, as well as the deployment of nanostructured silicon in industrially relevant engineering solutions. The proposed research establishes the fundamental understanding required by related device-level engineering efforts to develop next-generation photovoltaics, optical sensors, battery anodes, flexible electronics or nanoscale light-emitting diodes. In addition, the Kentucky-Karlsruhe collaboration will provide American students with hands-on laboratory experience in a world-class international research environment, German students with an opportunity to live and perform research in the USA, and all students the horizon-broadening opportunity to work with foreign peers in a science-focused cultural exchange.