Self-healing reduced graphene oxide films by supersonic kinetic spraying

The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide (r-GO) suspension. The r-GO flakes are used as received, which are pre-annealed and pre-hydrazine-treated, and do not undergo any post-treatment. A part of the considerable kinetic energy of the r-GO flakes entrained by the supersonic jet is used in stretching the flakes upon impact with the substrate. The resulting "frozen elastic strains" heal the defects (topological defects, namely Stone-Wales defect and C₂ vacancies) in the r-GO flakes, which is reflected in the reduced ratio of the intensities of the D and G bands in the deposited film. The defects can also be regenerated by annealing.