Conductivity enhancement of binder-based graphene inks by photonic annealing and subsequent compression rolling

This paper describes a combination of photonic annealing and compression rolling to improve the conductive properties of printed binder-based graphene inks. High-density light pulses result in temperatures up to 500°C that along with a decrease of resistivity lead to layer expansion. The structural integrity of the printed layers is restored using compression rolling resulting in smooth, dense, and highly conductive graphene films. The layers exhibit a sheet resistance of less than 1.4Ω□^-1 normalized to 25μm thickness. The proposed approach can potentially be used in a roll-to-roll manner with common substrates, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and paper, paving thereby the road toward high-volume graphene-printed electronics.