Large area coating of graphene at low temperature using a roll-to-roll microwave plasma chemical vapor deposition

Abstract Roll-to-roll microwave plasma chemical vapor deposition (CVD) at low temperature has been developed for the fabrication of a continuous and large area deposition of graphene films for the application of transparent conductive films. Deposition of graphene films on copper (Cu) foils, under methane (CH 4 ) and hydrogen (H 2 ) plasma below 380 °C, were confirmed and characterized by Raman spectroscopy. In addition, the film qualities were improved by controlling the CH 4 /(CH 4 + H 2 ) ratio and the process pressure. The graphene film obtained by roll-to-roll microwave plasma CVD process exhibited uniform Raman spectra towards the width direction of the Cu foil (A4 width). Transmittance and haze of the films were confirmed to be uniform and are in sufficient quality for the use of practical touch panel applications.