Chemical Vapor Deposition of Monolayer Graphene on Centimeter-Sized Cu(111) for Nanoelectronics Applications

We report a fast and straightforward preparation of centimeter-sized Cu(111) from polycrystalline Cu foil by the strain-free abnormal grain growth method and the subsequent growth of monolayer graphene by chemical vapor deposition (CVD). The fabrication of Cu(111) and graphene was streamlined into a straightforward process using a CVD system consisting of a tube furnace and a quartz boat. It was found that the annealing temperature and time are critical in the growth of Cu(111). Heating at 1060 °C for 3 h led to the conversion of polycrystalline Cu to Cu(111), yielding large grains and high-quality monolayer graphene. Molecular dynamics (MD) simulations supported the experimental findings, demonstrating that annealing leads to increased mobility of Cu grain boundaries. MD simulations further revealed that Cu(111) in the polycrystalline Cu serves as the seed for the growth of large Cu(111) grains. The impact of mechanical deformation on the conversion polycrystalline Cu to Cu(111) was also investigated, showing that a flat and nondeformed Cu foil was essential for the growth of large Cu(111) grains. The deformed areas could not be fully converted to Cu(111), a result which was further supported by MD simulations. Finally, the issue of Cu foil adhering to the quartz boat could be solved by flushing the CVD system with the working gases prior to annealing. The streamlined fabrication process for Cu(111) and monolayer graphene offers broad potential for applications such as nanoelectronics.