Fast growth of centimeter-scale single-crystal copper foils with high-index planes by the edge-incision effect: 2d Materials

Single-crystal copper substrates have gained importance for the preparation of high-quality graphene and hexagonal boron nitride monolayer films by chemical vapor deposition (CVD). Especially, large-scale single-crystal copper foils with high-index planes are synthesized recently and attract great interests. However, the current synthesis methods of single-crystal copper foils and films are energy and time-consuming. Here, we show a rapid and efficient approach for the preparation of centimeter-scale single-crystal copper foils by making small incisions at the edges of polycrystalline copper foils before high-temperature annealing. 1.5 cm x 4 cm pieces of grain-boundary-free copper foils can be prepared by annealing at 1080 degrees C for 60 min. The annealed copper foil manifests a single high-index plane and is grain-boundary-free over the whole area. We also show that CVD of graphene on the high-index single-crystal copper affords a higher growth rate than on low-index copper substrates.