Synthesis of CVD-graphene on rapidly heated copper foils†
Most chemical vapor deposition (CVD) systems used for graphene growth mainly employ convection and radiation heat transfer between the heating source and the metal catalyst in order to reach the activation temperature of the reaction, which in general leads to a long synthesis time and poor energy efficiency. Here, we report a highly time- and energy-efficient CVD setup, in which the metal catalyst (Cu) is designed to be physically contacted with a heating source to give quick heat transfer by conduction. The induced conduction heating enabled the usual effects of the pretreatment and annealing of Cu (i.e., annihilation of surface defects, impurities and contaminants) to be achieved in a significantly shorter time compared to conventional CVD. Notably, the rapid heating was observed to lead to larger grains of Cu with high uniformity as compared to the Cu annealed by conventional CVD, which are believed to be beneficial for the growth of high quality graphene. Through this CVD setup, bundles of high quality (∼252 Ω per square) and large area (over 16 inch) graphenes were able to be readily synthesized in 40 min in a significantly efficient way. When considering ease of scalability, high energy effectiveness and considerable productivity, our method is expected to be welcomed by industrialists.