▎ 摘 要
Surface passivation is proved to be an effective way to adjust material properties or to explore new two-dimensional (2D) materials. Herein, we proposed three hydrocarbons with high stability for the first time via hydrogenation on the Kagome graphene, namely, C6H4, C6H6-I, and C6H6-II. Unlike the Kagome graphene, which is metallic, all these 2D monolayers are wide-bandgap semiconductors (4.06-4.81 eV). Among them, C6H4 is an indirect bandgap semiconductor, but both C6H6-I and C6H6-II possess the direct bandgap feature. Considerable carrier mobilities (102 to 103 cm2 V-1 s-1) have been further confirmed in the three hydrocarbons on the basis of modified deformation potential theory. Specifically, for C6H4, the hole mobilities are as high as 104 to 105 cm2 V-1 s-1, comparable to those of graphene and black phosphorus. The intrinsic vertical electric field induced by the asymmetric crystal structures in C6H4 and C6H6-I will be beneficial to the spatial separation of electrons and holes in semiconductors, promising in the field of optoelectronics. In addition, hydrogenation has a great influence on the mechanical properties of Kagome graphene, no matter whether it is Young's modulus, Poisson's ratio, or ideal tensile strength. Particularly, in-plane axial negative Poisson's ratios (-0.011/-0.018 along the a-/b-direction) were found in C6H6-I, mainly originated from the interaction of carbon pentagons and octagons. These interesting findings in our work may pave the way for the application of hydrogenated Kagome graphene in the future.