그래핀을 통한 기판 표면의 결정 정보 투과 현상

Abstract

Here, we demonstrated the transparency of graphene to the atomic arrangement of a substrate surface, i.e., the lattice transparency of graphene, by using hydrothermally grown ZnOnanorods as a model system. The growth behaviors of ZnO nanocrystals on graphene-coated and uncoated substrates with various crystal structures were investigated. The atomic arrangements of the nucleating ZnO nanocrystals exhibited a close match with those of the respective substrates despite the substrates being bound to the other side of the graphene. By using first-principles calculations based on density functional theory, we confirmed the energetic favorability of the nucleating phase following the atomic arrangement of the substrate even with the graphene layer present in between. We also found thatthe lattice transparency depends critically on its interface with a supporting substrate. Graphene showed lattice transparency when supported on an atomically flat substrate whereas it became completely opaque when suspended on a substrate with nanoscale topography. In addition to transmitting information about the atomic lattice of the substrate, graphene also protected its surface. This dual role enabled the hydrothermal growth of ZnOnanorods on a Cu substrate, which otherwise dissolved in the reaction conditions when graphene was absent.