AI 中文总结
研究利用高分辨率斑点轮廓分析低能电子衍射，确定等离子体增强化学气相沉积在蓝宝石上生长的少层石墨烯平均晶粒尺寸，生长后退火可增大晶粒尺寸，该方法能量化绝缘衬底上石墨烯结构相干性。
AI 中文摘要
我们展示了使用高分辨率斑点轮廓分析低能电子衍射来确定等离子体增强化学气相沉积生长在蓝宝石（Al₂O₃）上的少层石墨烯的平均晶粒尺寸。衍射图案显示出变宽的石墨烯斑点、明显的漫散射和方位扩展特征，表明有限的微晶尺寸和旋转无序。通过用艾里型衍射轮廓分析镜面（00）斑点的有限尺寸展宽，我们确定生长态石墨烯层的平均晶粒直径为3.7nm。超高真空条件下的生长后退火分别将平均晶粒尺寸增加到约5.7nm和6.8nm。这些结果确立了斑点轮廓分析低能电子衍射作为一种敏感的倒易空间方法，用于量化直接生长在绝缘衬底上的石墨烯的结构相干性。
英文摘要
We demonstrate the use of high-resolution spot-profile analysis low-energy electron diffraction to determine the mean grain size of plasma-enhanced chemical vapor deposition grown few-layer graphene on sapphire (Al$_2$O$_3$). The diffraction patterns exhibit broadened graphene spots, pronounced diffuse scattering, and azimuthally extended features, indicating finite crystallite size and rotational disorder. By analyzing the finite-size broadening of the specular (00) spot with an Airy-type diffraction profile, we determine a mean grain diameter of 3.7$\,$nm for the as-grown graphene layer. Post-growth annealing under ultrahigh-vacuum conditions increases the mean grain size to about 5.7$\,$nm and 6.8$\,$nm, respectively. These results establish SPA-LEED as a sensitive reciprocal-space method for quantifying the structural coherence of directly grown graphene on insulating substrates.
CommentsThe following article has been submitted to Applied Physics Letters
