We report the successful preparation of a purely honeycomb, graphene-like borophene, by using an Al(1 1 1) surface as the substrate and molecular beam epitaxy (MBE) growth in ultrahigh vacuum. Scanning tunneling microscopy (STM) images reveal perfect monolayer borophene with planar, non-buckled honeycomb lattice similar as graphene. Theoretical calculations show that the honeycomb borophene on Al(1 1 1) is energetically stable. Remarkably, nearly one electron charge is transferred to each boron atom from the Al(1 1 1) substrate and stabilizes the honeycomb borophene structure, in contrast to the negligible charge transfer in case of borophene/Ag(1 1 1). The existence of honeycomb 2D allotrope is important to the basic understanding of boron chemistry, and it also provides an ideal platform for fabricating boron-based materials with intriguing electronic properties such as Dirac states.

我们报告了通过使用 Al(1 1 1) 表面作为基底和超高真空中的分子束外延 (MBE) 生长，成功制备了纯蜂窝状石墨烯类硼烯。扫描隧道显微镜 (STM) 图像揭示了完美的单层硼烯，其具有类似于石墨烯的平面、非屈曲蜂窝状晶格。理论计算表明，Al(1 1 1) 上的蜂窝状硼烯在能量上是稳定的。值得注意的是，将近一个电子电荷从 Al(1 1 1) 基板转移到每个硼原子并稳定蜂窝状硼烯结构，这与硼烯/Ag(1 1 1) 的情况下电荷转移可忽略不计形成对比。蜂窝二维同素异形体的存在对于硼化学的基本理解很重要，