Crossover of 2D graphene and 3D carbon island growth on Cu–In alloy surface

Abstract

Nucleation and initial stage of graphene growth in chemical vapor deposition on the Cu–In alloy surface were studied by in situ scanning electron microscopy together with ex situ Auger electron microscopy, atomic force microscopy, and Raman spectroscopy. Because of the lower melting point of Cu–In alloy, around 800°C depending on the In content, growth on solid and liquid Cu–In surfaces could be compared. On both the solid and liquid surfaces, 2D graphene and 3D carbon island growth coexisted in the initial stage. On a wide terrace, 3D carbon island nucleation dominated over 2D graphene nucleation and 3D carbon islands showed dendritic growth. When the bare area on the Cu–In surface became narrow with an increase in the island coverage, 2D graphene nucleation and growth dominated. The growth mode change from 3D to 2D was attributed to the reduction of carbon adatom flux to the existing islands due to depletion of supersaturation and reduction of the size of bare metal surface.