论文信息
【标题】Borophene synthesis beyond the single-atomic-layer limit
【作者】Xiaolong Liu, Qiucheng Li, Qiyuan Ruan, Matthew S. Rahn, Boris I. Yakobson & Mark C. Hersam
【期刊】Nature Materials
【时间】26-Aug-2021
【链接】https://www.nature.com/articles/s41563-021-01084-2
【DOI】https://doi.org/10.1038/s41563-021-01084-2
【摘要】Synthetic two-dimensional (2D) materials have no bulk counterparts and typically exist as single atomic layers due to substrate-stabilized growth. Multilayer formation, although broadly sought for structure and property tuning, has not yet been achieved in the case of synthetic 2D boron: that is, borophene. Here, we experimentally demonstrate the synthesis of an atomically well-defined borophene polymorph beyond the single-atomic-layer (SL) limit. The structure of this bilayer (BL) borophene is consistent with two covalently bonded α-phase layers (termed BL-α borophene) as evidenced from bond-resolved scanning tunnelling microscopy, non-contact atomic force microscopy and density functional theory calculations. While the electronic density of states near the Fermi level of BL-α borophene is similar to SL borophene polymorphs, field-emission resonance spectroscopy reveals distinct interfacial charge transfer doping and a heightened local work function exceeding 5 eV. The extension of borophene polymorphs beyond the SL limit significantly expands the phase space for boron-based nanomaterials.
