Ion beam irradiation of few-layer graphene and its application to liquid crystal cells

Few-layer graphene was irradiated with a low-energy Ar+ ion beam and applied to liquid crystal (LC) cells as both a transparent electrode and a homogeneous alignment enhancer. The optimum conditions for ion-beam-irradiated few-layer graphene (I-G) are 80eV of beam energy and 1s of irradiation time, which is confirmed by the decrease of the sheet resistance and increase of water contact angle with similar transmittance to pristine few-layer graphene. It is shown that the ion beam treatment of few-layer graphene under optimized conditions removes the surface contaminants and flattens the surface without damages. LC cells on I-G show similar device performance to that of LC cells based on indium tin oxide (ITO) with rubbing-treated polyimide. These results are very encouraging for replacing ITO electrodes with few-layer graphene in LC display applications.