论文标题
外延石墨烯中碳化硅碳化物堆叠式诱导的掺杂变化
Silicon carbide stacking-order-induced doping variation in epitaxial graphene
论文作者
论文摘要
通常，假定外延石墨烯中的费米水平受两种效应的控制：p型极化掺杂由大部分六边形SIC（0001）底物引起，并由与缓冲层相关的供体样状态过度补偿。在这项工作中，我们证明这种效果也与特定的基础SIC露台有关。我们制造了一个非相同SIC梯田的周期性序列，该序列明确归因于特定的SIC表面终止。实验观察到SIC终止与电子石墨烯特性之间的明显相关性，并通过各种互补的表面敏感方法确认。我们将这种相关性归因于SIC终止依赖性极化掺杂在上覆石墨烯层的接近效应。我们的发现为通过介电极性底物上的外延石墨烯和其他2D层的自我模式开辟了一种新方法，用于纳米级掺杂工程。
Generally, it is supposed that the Fermi level in epitaxial graphene is controlled by two effects: p-type polarization doping induced by the bulk of the hexagonal SiC(0001) substrate and overcompensation by donor-like states related to the buffer layer. In this work, we evidence that this effect is also related to the specific underlying SiC terrace. We fabricated a periodic sequence of non-identical SiC terraces, which are unambiguously attributed to specific SiC surface terminations. A clear correlation between the SiC termination and the electronic graphene properties is experimentally observed and confirmed by various complementary surface-sensitive methods. We attribute this correlation to a proximity effect of the SiC termination-dependent polarization doping on the overlying graphene layer. Our findings open a new approach for a nano-scale doping-engineering by self-patterning of epitaxial graphene and other 2D layers on dielectric polar substrates.
