同轴多壳半导体纳米丝脆韧断裂行为及变形机理研究

项目名称： 同轴多壳半导体纳米丝脆韧断裂行为及变形机理研究

项目编号： No.11302161

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 刘群峰

作者单位： 西安交通大学

项目金额： 30万元

中文摘要： 同轴多壳半导体纳米丝作为一种新颖的纳米元件，具有优异的电学、光学和半导体特性，有望大量应用于纳机电系统（NEMS）中。半导体纳米丝的力学行为决定了纳机电系统的稳定性和可靠性。本申请项目拟采用分子动力学方法，研究具有不同截面形状和表面形态硅纳米丝的脆性、韧性断裂行为，与实验结果对比讨论其变形机理。在此基础上，研究具有单晶硅核心和半导体外壳的"芯-壳"型半导体纳米丝的断裂行为和变形机理，结合实验结果揭示表/界面对半导体纳米丝变形机理的影响。最后，将计算模拟与理论分析结合，建立考虑表/界面弹性的同轴多壳纳米丝的理论模型，为同轴多壳半导体纳米丝的设计提供理论参考和应用指导。

中文关键词： 纳米结构；力学行为；表面效应；界面效应；热传导

英文摘要： Coaxial multi-shell semiconductor nanowires have recently attracted great attention for their distinctive electrical, optical and semiconductor properties and are envisioned as fundamental building blocks of future nano-electro-mechanical systems (NEMS). The reliability and robustness of NEMS is determined by the mechanical properties of its building blocks. The current proposed project will first study effects of cross-sectional shape and surface morphology on fracture behaviors of silicon nanowires by using molecular dynamics method, and then discuss their deformation mechanism by comparing simulations with experimental results. Secondly, fracture behaviors of 'core-shell' type nanowires, with the same silicon 'core' and different conductor 'shell', will be investigated. By performing atomistic simulations and experimental tests, the proposed project is intend to explore the roles of outermost surface and different inter-shell interfaces in determining the deformation mechanism of silicon nanowires. Finally, the mechanical properties of coaxial multi-shell silicon nanowires will be investigated theoretically and computationally, and a continuum theoretic foumulation, including the surface and interface elasticity, is to be provided. This research not only possesses high academic significance in revealing surfa

英文关键词： Nanostructures；Mechanical behavior；Surface effect；Interface effect；Thermal transfer