Inducing electronic changes in graphene through silicon (100) substrate modification.
Inducing electronic changes in graphene through silicon (100) substrate modification.
复制标题
DOI：
10.1021/nl201022t
复制
发表时间：
2011-06
期刊：
影响因子：
10.8
通讯作者：
Yang Xu;K. He;S. Schmucker;Zhendong Guo;J. Koepke;Joshua D. Wood;J. Lyding;N. Aluru
中科院分区：
文献类型：
--
作者：
Yang Xu;K. He;S. Schmucker;Zhendong Guo;J. Koepke;Joshua D. Wood;J. Lyding;N. Aluru
我们已经在清洁和氢(H)钝化硅（100）（Si(100)/H）表面上对石墨烯单层进行了扫描隧道显微镜和光谱（STM/STS）测量以及从头计算。为了实验研究两种衬底上相同的石墨烯片，我们开发了一种从Si(100)/H表面的石墨烯单层下脱氢的方法。我们的工作首次证明了通过电子刺激解吸，在Si(100)/H上从单层石墨烯片下成功地再现了氢的脱钝化。从头算模拟与氢解吸前后的STS结合表明，石墨烯与清洁和h钝化的Si（100）表面的相互作用不同。Si(100)/H表面不会干扰石墨烯的电子特性，而干净的Si（100）表面与石墨烯之间的相互作用会显著改变石墨烯的电子态。这种效应是由于C和表面Si原子之间的共价键作用，改变了石墨烯层的π轨道网络。局域态密度表明，在费米能量附近，键合的C和Si表面态受到高度干扰。
We have performed scanning tunneling microscopy and spectroscopy (STM/STS) measurements as well as ab initio calculations for graphene monolayers on clean and hydrogen(H)-passivated silicon (100) (Si(100)/H) surfaces. In order to experimentally study the same graphene piece on both substrates, we develop a method to depassivate hydrogen from under graphene monolayers on the Si(100)/H surface. Our work represents the first demonstration of successful and reproducible depassivation of hydrogen from beneath monolayer graphene flakes on Si(100)/H by electron-stimulated desorption. Ab initio simulations combined with STS taken before and after hydrogen desorption demonstrate that graphene interacts differently with the clean and H-passivated Si(100) surfaces. The Si(100)/H surface does not perturb the electronic properties of graphene, whereas the interaction between the clean Si(100) surface and graphene changes the electronic states of graphene significantly. This effect results from the covalent bonding between C and surface Si atoms, modifying the π-orbital network of the graphene layer. The local density of states shows that the bonded C and Si surface states are highly disturbed near the Fermi energy.