Rotated domains in chemical vapor deposition-grown monolayer graphene on Cu(111): an angle-resolved photoemission study
Rotated domains in chemical vapor deposition-grown monolayer graphene on Cu(111): an angle-resolved photoemission study
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DOI：
10.1039/c3nr01700a
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发表时间：
2013-01-01
期刊：
影响因子：
6.7
通讯作者：
Hwang, Chan-Cuk
中科院分区：
文献类型：
--
作者：
Jeon, Cheolho;Hwang, Han-Na;Hwang, Chan-Cuk
铜被认为是最有希望通过化学气相沉积（CVD）生长高质量和大面积石墨烯的衬底，特别是在（111）面。由于石墨烯和Cu衬底之间的相互作用影响了合成石墨烯的取向、质量和性能，我们使用角分辨光发射光谱研究了相互作用。测量了Cu（111）的肖克利表面态和石墨烯的p带从CVD生长的初始阶段到单层形成的演变过程。石墨烯生长沿着Cu（111）晶格开始，在K点处狄拉克能带穿过费米能（E-F），而没有与Cu的d能带杂交。然后，随着石墨烯覆盖的区域变得更宽，两个旋转的畴也随之生长。狄拉克能约为-0.4 eV，铜（111）的肖克利表面态能量在石墨烯形成后向EF方向移动了约0.15 eV。这些结果表明石墨烯和Cu之间存在弱相互作用，并且电子转移仅限于Cu（111）的肖克利表面态和石墨烯的p带之间的电子转移。石墨烯和Cu之间的弱相互作用和轻微的晶格失配导致石墨烯畴的旋转生长（9.6度和8.4度），在不同取向的狄拉克带中没有显着差异。这些旋转的石墨烯畴导致了晶界，这将阻碍铜衬底上大尺寸单层的生长。
Copper is considered to be the most promising substrate for the growth of high-quality and large area graphene by chemical vapor deposition (CVD), in particular, on the (111) facet. Because the interactions between graphene and Cu substrates influence the orientation, quality, and properties of the synthesized graphene, we studied the interactions using angle-resolved photoemission spectroscopy. The evolution of both the Shockley surface state of the Cu(111) and the p band of the graphene was measured from the initial stage of CVD growth to the formation of a monolayer. Graphene growth was initiated along the Cu(111) lattice, where the Dirac band crossed the Fermi energy (E-F) at the K point without hybridization with the d-band of Cu. Then two rotated domains were additionally grown as the area covered with graphene became wider. The Dirac energy was about -0.4 eV and the energy of the Shockley surface state of Cu(111) shifted toward the EF by similar to 0.15 eV upon graphene formation. These results indicate weak interactions between graphene and Cu, and that the electron transfer is limited to that between the Shockley surface state of Cu(111) and the p band of graphene. This weak interaction and slight lattice mismatch between graphene and Cu resulted in the growth of rotated graphene domains (9.6 degrees and 8.4 degrees), which showed no significant differences in the Dirac band with respect to different orientations. These rotated graphene domains resulted in grain boundaries which would hinder a large-sized single monolayer growth on Cu substrates.