Nat Mater. 2012 Feb 5;11(4):294-300. doi: 10.1038/nmat3245.
The quest for materials capable of realizing the next generation of electronic and photonic devices continues to fuel research on the electronic, optical and vibrational properties of graphene. Few-layer graphene (FLG) flakes with less than ten layers each show a distinctive band structure. Thus, there is an increasing interest in the physics and applications of FLGs. Raman spectroscopy is one of the most useful and versatile tools to probe graphene samples. Here, we uncover the interlayer shear mode of FLGs, ranging from bilayer graphene (BLG) to bulk graphite, and suggest that the corresponding Raman peak measures the interlayer coupling. This peak scales from ~43 cm(-1) in bulk graphite to ~31 cm(-1) in BLG. Its low energy makes it sensitive to near-Dirac point quasiparticles. Similar shear modes are expected in all layered materials, providing a direct probe of interlayer interactions.
追求能够实现下一代电子和光子器件的材料，继续推动对石墨烯的电子、光学和振动特性的研究。具有少于十层的少层石墨烯 (FLG) 薄片显示出独特的能带结构。因此，人们对 FLG 的物理和应用越来越感兴趣。拉曼光谱是探测石墨烯样品最有用和多功能的工具之一。在这里，我们揭示了从双层石墨烯 (BLG) 到块状石墨的 FLG 的层间剪切模式，并提出相应的拉曼峰测量层间耦合。该峰的范围从块状石墨中的43cm(-1)到 BLG 中的31cm(-1)。其低能量使其对近狄拉克点准粒子敏感。预计所有层状材料中都会出现类似的剪切模式，为层间相互作用提供直接的探测手段。
