Structural chirality, defined as the lack of mirror symmetry in materials’ atomic structure, is only meaningful in three-dimensional space. Yet two-dimensional (2D) materials, despite their small thickness, can show chirality that enables prominent asymmetric optical, electrical and magnetic properties. In this Perspective, we first discuss the possible definition and mathematical description of ‘2D chiral materials’, and the intriguing physics enabled by structural chirality in van der Waals 2D homobilayers and heterostructures, such as circular dichroism, chiral plasmons and the nonlinear Hall effect. We then summarize the recent experimental progress and approaches to induce and control structural chirality in 2D materials from monolayers to superlattices. Finally, we postulate a few unique opportunities offered by 2D chiral materials, the synthesis and new properties of which can potentially lead to chiral optoelectronic devices and possibly materials for enantioselective photochemistry.

结构手性定义为材料原子结构缺乏镜像对称性，仅在三维空间中才有意义。然而，二维 (2D) 材料尽管厚度很小，却可以表现出手性，从而实现显着的不对称光学、电学和磁学特性。在本视角中，我们首先讨论“二维手性材料”的可能定义和数学描述，以及范德华二维同双层和异质结构中的结构手性所带来的有趣物理学，例如圆二色性、手性等离子体和非线性霍尔效应。然后，我们总结了最近的实验进展和诱导和控制从单层到超晶格的二维材料结构手性的方法。最后，我们假设二维手性材料提供了一些独特的机会，其合成和新特性可能会导致手性光电器件和可能的对映选择性光化学材料。