Silicene, germanene and stanene are part of a monoelemental class of two-dimensional (2D) crystals termed 2D-Xenes (X = Si, Ge, Sn and so on) which, together with their ligand-functionalized derivatives referred to as Xanes, are comprised of group IVA atoms arranged in a honeycomb lattice — similar to graphene but with varying degrees of buckling. Their electronic structure ranges from trivial insulators, to semiconductors with tunable gaps, to semi-metallic, depending on the substrate, chemical functionalization and strain. More than a dozen different topological insulator states are predicted to emerge, including the quantum spin Hall state at room temperature, which, if realized, would enable new classes of nanoelectronic and spintronic devices, such as the topological field-effect transistor. The electronic structure can be tuned, for example, by changing the group IVA element, the degree of spin–orbit coupling, the functionalization chemistry or the substrate, making the 2D-Xene systems promising multifunctional 2D materials for nanotechnology. This Perspective highlights the current state of the art and future opportunities in the manipulation and stability of these materials, their functions and applications, and novel device concepts.

硅，锗和锡是称为2D-Xenes（X = Si，Ge，Sn等）的二维（2D）晶体的单元素类的一部分，它们与它们的配体官能化衍生物（称为Xanes）一起构成由排列在蜂窝晶格中的IVA组原子组成-与石墨烯相似，但具有不同的屈曲度。它们的电子结构从琐碎的绝缘体到具有可调间隙的半导体，再到半金属，具体取决于衬底，化学功能化和应变。预计将出现十多种不同的拓扑绝缘体状态，包括室温下的量子自旋霍尔状态，如果实现，它将使新型的纳米电子和自旋电子器件成为可能，例如拓扑场效应晶体管。可以调整电子结构，例如，通过改变IVA族元素，自旋-轨道耦合程度，功能化化学物质或基质，使得2D-Xene系统有望成为用于纳米技术的多功能2D材料。本《观点》重点介绍了这些材料的操作和稳定性，其功能和应用以及新颖的设备概念的最新技术和未来机会。