Atomic mechanism of strong interactions at the graphene/sapphire interface

• Published in: Nature communications Vol. 10; no. 1; pp. 5013 - 5
• Main Authors: Dou, Zhipeng, Chen, Zhaolong, Li, Ning, Yang, Shenyuan, Yu, Zhiwei, Sun, Yuanwei, Li, Yuehui, Liu, Bingyao, Luo, Qiang, Ma, Tianbao, Liao, Lei, Liu, Zhongfan, Gao, Peng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.11.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 140/146; 147/143; 147/3; 639/301/357/1018; 639/301/357/918; 639/766/119/544; Electronic devices; Electronic equipment; Epitaxial growth; Film growth; Graphene; High temperature; Humanities and Social Sciences; multidisciplinary; Remote control; Sapphire; Science; Science (multidisciplinary); Strong interactions (field theory); Substrates; Thin films; Two dimensional materials
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13023-6

For atomically thin two-dimensional materials, interfacial effects may dominate the entire response of devices, because most of the atoms are in the interface/surface. Graphene/sapphire has great application in electronic devices and semiconductor thin-film growth, but the nature of this interface is largely unknown. Here we find that the sapphire surface has a strong interaction with some of the carbon atoms in graphene to form a C-O-Al configuration, indicating that the interface interaction is no longer a simple van der Waals interaction. In addition, the structural relaxation of sapphire near the interface is significantly suppressed and very different from that of a bare sapphire surface. Such an interfacial C-O-Al bond is formed during graphene growth at high temperature. Our study provides valuable insights into understanding the electronic structures of graphene on sapphire and remote control of epitaxy growth of thin films by using a graphene–sapphire substrate. Understanding the atomic arrangement and binding nature of 2D materials with substrates is crucial to understand their properties and utilize their functions. Here, authors report that at high temperature graphene and α-Al 2 O 3 substrate form a C-O-Al bond, having strong interactions, while interfacial structural relaxations of sapphire remain suppressed.