In this report we demonstrate a method for direct determination of the number of layers of hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on semiinsulating vanadium-compensated on-axis 6H-SiC(0001). The method anticipates that the intensity of the substrate’s Raman-active longitudinal optical A₁ mode at 964 cm⁻¹ is attenuated by 2.3% each time the light passes through a single graphene layer. Normalized to its value in a graphene-free region, the A₁ mode relative intensity provides a greatly enhanced topographic image of graphene and points out to the number of its layers within the terraces and step edges, making the technique a reliable diagnostic tool for applied research.

在本报告中，我们展示了一种直接测定半绝缘钒补偿同轴 6H-SiC(0001) 上的氢插层准独立外延化学气相沉积石墨烯层数的方法。该方法预计，每次光通过单个石墨烯层时，衬底的拉曼活性纵向光学A ₁模式在 964 cm ^-1处的强度衰减 2.3%。归一化为无石墨烯区域中的值，A ₁模式相对强度提供了大大增强的石墨烯地形图像，并指出了它在阶地和台阶边缘内的层数，使该技术成为应用的可靠诊断工具研究。