Nanocrystalline carbon film electrodes generated and patterned by UV-laserablation of polystyrene

A carbon conductive film consisting of nanometer sized domains has been pat terned by scanning photoablation of polystyrene. The film formation involve s the photoablation of a highly insulating polymer, and the redeposition of conductive carbon fragments. This film has been investigated by scanning e lectron microscopy, atomic force microscopy, microRaman spectroscopy, elect rical conductivity and standard electrochemical measurements. Film depositi on under different gas flow conditions has revealed major differences in th e electrical and electrochemical properties of the material. Cyclic voltamm etry and double layer capacitance measurements have indicated the formation of a conductive layer with a high specific area when generated in ambient atmosphere. Inert atmospheres like nitrogen and argon lead to conducting fi lms with low double layer capacitance values (10 mu F cm(-2)), whereas an a ir atmosphere leads to conducting films with supercapacitance values (5 mF cm(-2)). This large difference in capacitances is discussed in terms of the photochemical effects of the ambient atmosphere during the polymer treatme nt.