Clean and efficient transfer of CVD-grown graphene by electrochemical etching of metal substrate

An electrochemical etching technique was developed to achieve a clean and efficient transfer of large-area graphene films grown on copper foils by chemical vapor deposition without degrading the quality of graphene. Clean transfer for continuous graphene films with fewer impurities and unintentional p-type doping in comparison with conventional wet-etching in oxidant solutions was confirmed by optical microscopy, scanning electron microscopy, atomic force microscopy, ultraviolet–visible spectroscopy, and Raman spectroscopy. This electrochemical transfer technique can be scaled up for industrial use and generalized to various substrates by selecting suitable oxidation voltage and electrolytes, which opens the door for the fabrication of large-scale graphene devices with enhanced performance.