Direct graphene synthesis on polymer films and its application to flexible devices

Abstract

Flexible electronic devices, such as flexible displays and wearable sensors, has shown rapid growth over the last decade [1]. Graphene is a promising material for the flexible devices, due to its high carrier mobility, flexibility and optical transparency [2]. Graphene device has been fabricated mostly through the process including thermal chemical vapor deposition so far, although the process requires feeding reactive hydrocarbon (HC) gases, graphene transferring from catalytic metal substrates and plasma etching of graphene which often induces damage to the material [3]. Recently, the authors conducted direct synthesis of graphene from amorphous carbon (a-C)/catalytic nickel bilayer on solid device substrates, using thermal annealing [4] and laser annealing [5]. Here we report direct graphene synthesis from Ni-coated polyethylene naphthalate (PEN) film using position-controlled laser annealing. Carbon sources, i.e. HC or a-C, are no longer required in this method, since carbon atoms are fed from the PEN film substrates. This method also drastically simplifies the device fabrication process, that is, graphene FET and graphene strain sensor were completed just after laser irradiation to Ni-patterned PEN film.