Graphene growth kinetics for CO2 laser carbonization of polyimide

•The crystallite size of graphene obtained from laser carbonization of Polyimide was controlled by varying laser fluence and scan speed.•Laser irradiation temperature was calculated by photothermal model in COMSOL and controlled by varying laser fluence.•Laser irradiation time was controlled by varying laser scan speed.•Growth rate of graphene was formulated using Arrhenius classic kinetic model from which the activation energy of laser carbonization from Polyimide was calculated.