Abstract：
The successful synthesis of borophene beyond the monolayer limit has expanded the family of two-dimensional boron nanomaterials. While atomic-resolution topographic imaging has been previously reported, vibrational mapping has the potential to reveal deeper insight into the chemical bonding and electronic properties of bilayer borophene. Herein, inelastic electron tunneling spectroscopy (IETS) is used to resolve the low-energy vibrational and electronic properties of bilayer-α (BL-α) borophene on Ag(111) at the atomic scale. Using a carbon monoxide (CO)-functionalized scanning tunneling microscopy tip, the BL-α borophene IETS spectra reveal unique features compared to single-layer borophene and typical CO vibrations on metal surfaces. Distinct vibrational spectra are further observed for hollow and filled boron hexagons within the BL-α borophene unit cell, providing evidence for interlayer bonding between the constituent borophene layers. These experimental results are compared with density functional theory calculations to elucidate the interplay between the vibrational modes and electronic states in bilayer borophene.
摘要：
超过单层极限的硼苯的成功合成扩展了二维硼纳米材料的家族。虽然以前已经报道了原子分辨率地形成像，振动映射有可能揭示更深入的了解双层硼苯的化学键和电子性质。在这里，非弹性电子隧穿谱（IETS）用于在原子尺度上解析Ag（111）上双层-α（BL-α）硼苯的低能振动和电子性质。使用一氧化碳（CO）功能化的扫描隧道显微镜尖端，与单层硼苯和金属表面上的典型CO振动相比，BL-α硼苯IETS光谱揭示了独特的特征。进一步观察到BL-α硼苯晶胞内中空和填充的硼六边形的明显振动光谱，为组成的硼酚层之间的层间结合提供证据。将这些实验结果与密度泛函理论计算进行比较，以阐明双层硼苯中振动模式和电子态之间的相互作用。
