中文摘要：

晶体材料中的缺陷会引发局部的形变与应力，从而对材料力学性质、输运行为等物理特性产生影响，这在低维材料中尤为显著．近几年来在石墨烯等二维材料的相关研究中发现了多种类型的缺陷，这些缺陷对其材料性能具有一定的调控功能，且与块体材料中的行为有一定区别，因而其物理机制值得探究．本文将介绍相关的研究进展，特别是缺陷在影响材料行为时的几何与拓扑效应，并讨论其在二维材料晶体生长、低维结构材料设计等方面的意义．

英文摘要：

Two-dimensional （2D） materials have been envisioned as wonder materials not only because of their fantastic properties, but also due to their unique role as model materials for fundamental research of 2D physics. In this article, I will discuss the topological and geometrical effects of defects in modulating the structures and mechanical responses of 2D materials using graphene as an example. We conclude that as the dimension is reduced, imperfections become vital for the material behaviors compared to those in the bulk. These effects have further implications in modulating the growth and assembly of graphene single-crystal domains into continuum films. The constructive aspect of defects in engineering 2D materials with designed pre-stress and geometry will also be discussed.