Microscopic thickness determination of thin graphite films formed on SiC from quantized oscillation in reflectivity of low-energy electrons
Microscopic thickness determination of thin graphite films formed on SiC from quantized oscillation in reflectivity of low-energy electrons
复制标题
DOI：
10.1103/physrevb.77.075413
复制
发表时间：
2008-02-01
影响因子：
3.7
通讯作者：
Yamaguchi, H.
中科院分区：
文献类型：
--
作者：
Hibino, H.;Kageshima, H.;Yamaguchi, H.
低能电子显微镜（LEEM）用于测量石墨化SiC低能电子的反射率（0001）。反射率表现出明显的量子化振荡，是电子能量和石墨厚度的函数。石墨薄膜中的导带形成离散能级，其波矢量垂直于表面。入射电子与这些量子化导带状态的共振增强了电子通过薄膜进入SiC衬底的传输，导致反射率下降。利用紧密结合和第一性原理计算可以很好地解释倾角位置。石墨的厚度分布可以通过LEEM反射率测量在微观上确定。
Low-energy electron microscopy (LEEM) was used to measure the reflectivity of low-energy electrons from graphitized SiC(0001). The reflectivity shows distinct quantized oscillations as a function of the electron energy and graphite thickness. Conduction bands in thin graphite films form discrete energy levels whose wave vectors are normal to the surface. Resonance of the incident electrons with these quantized conduction band states enhances electrons to transmit through the film into the SiC substrate, resulting in dips in the reflectivity. The dip positions are well explained using tight-binding and first-principles calculations. The graphite thickness distribution can be determined microscopically from LEEM reflectivity measurements.