考虑弹性表面效应的III-V纳米材料中位错消除的机理

基于III-V族元素的纳米材料以其优异的光电性能被普遍认为是最具潜力的取代传统硅材料的下一代新型半导体材料，但是实际生产或实验得到的样品力学性能并不完善，其中最普遍的内部结构缺陷就是由位错引起的。纳米材料中，表面应力对位错的影响不容忽视。不同于常见的处理简单二维各向同性材料的复变函数势方法，本项目创新地建立三维各向异性材料中弹性表面和位错相互作用下应力应变场的求解模型，并结合采用分子动力学和第一性原理模拟计算得到的表面弹性系数，最终应用于表面应力作用下新型半导体纳米材料中位错消除机理的研究，从而提出控制位错产生的参数优化设计准则。其成果可以为制备高质量甚至零位错新型半导体材料提供设计思路或者指导方向。

III-V elements-based novel semiconductor nanomaterials are widely regarded as the most promising substitutes of conventional silicon-based materials due to their excellent optoelectronic properties. However, the samples prepared by practical fabrications or experiments usually have poor mechanical properties, and the most common structural defects are due to dislocations. For nanomaterials, surface stress effect on dislocations should not be neglected. Different from the common complex variable method for simple 2D isotropic materials, this project will propose a novel model for solving the stress and strain field due to the interaction between surface elasticity and dislocation in 3D anisotropic materials. By combining results of surface elasticity tensors from molecular dynamics and first principle calculations, this project will focus on the investigation of dislocation dissipation mechanism in novel semiconductor nanomaterials with surface stress effect, and pursue the optimal parameter design for controlling the generation of dislocations. The outcome of this project could provide guidelines for the fabrication of high-quality or even dislocation-free novel semiconductor nanomaterials.