Growth and electronic structure of 2D hexagonal nanosheets on a corrugated rectangular substrate
Growth and electronic structure of 2D hexagonal nanosheets on a corrugated rectangular substrate
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DOI：
10.1088/1361-6528/aadfd2
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发表时间：
2018-10
期刊：
影响因子：
3.5
通讯作者：
S. Achilli;E. Cavaliere;Thanh-hai Nguyen;M. Cattelan;S. Agnoli
中科院分区：
文献类型：
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作者：
S. Achilli;E. Cavaliere;Thanh-hai Nguyen;M. Cattelan;S. Agnoli
石墨烯和 h-BN 在超高真空条件下通过化学气相沉积在 Pt(110) 表面生长。扫描隧道显微镜测量和低能电子衍射数据表明，石墨烯形成了各种不同取向的不通约域，尽管其[ 11 2 ´ 0 ]方向与Pt的[ 00 1 ´ ]方向具有强烈的对齐倾向。同时，h-BN 表现出与 c(8 × 10) 相当的超结构，其呈现出高水平的缺陷率，这意味着周期性的局部变化（即混合的 c(8 × 10) 和 c(8 × 12) 斑块）和局部缺陷的引入。先进的光电子能谱数据（来自价带的角分辨光电子能谱）和从头计算相结合表明，两种二维材料与基底的相互作用都很弱：石墨烯表现出中性掺杂并且形态平坦，即使它在相对高度波纹的矩形（110）表面上成核。在 h-BN 的情况下，相互作用稍强，其特征是从表面 Pt 原子到氮原子的少量电子转移。因此，Pt 的 (110) 端接对于二维材料的生长来说是一个非常有趣的表面，因为鉴于其低对称性，它可能有利于选择性取向域的生长，但不会影响其原始电子特性。
Graphene and h-BN are grown by chemical vapor deposition in ultra high vacuum conditions on the Pt(110) surface. Scanning tunneling microscopy measurements and low-energy electron diffraction data indicate that graphene forms a variety of differently oriented incommensurate domains although with a strong preference to align its [ 11 2 ¯ 0 ] direction with the [ 00 1 ¯ ] direction of Pt. Meanwhile, h-BN exhibits a c(8 × 10) commensurate superstructure, which presents a high level of defectivity that implies local variation of the periodicity (i.e. mixed c(8 × 10) and c(8 × 12) patches) and the introduction of local defects. The combination of advanced photoemission spectroscopy data (angle-resolved photoemission spectroscopy from the valence band) and ab initio calculations indicates that both 2D materials interact weakly with the substrate: graphene exhibits neutral doping and is morphologically flat, even if it nucleates on the relatively highly corrugated rectangular (110) surface. In the case of h-BN, the interaction is slightly stronger and is characterized by a small electron transfer from surface Pt atoms to nitrogen atoms. The (110) termination of Pt is therefore a quite interesting surface for the growth of 2D materials because given its low symmetry, it may favor the growth of selectively oriented domains but does not affect their pristine electronic properties.