Laser Patterned Graphene Electronic Devices on Graphene Oxide Films Derived from Natural Carbon Feedstocks*

Recent research has shown that laser irradiation of graphene oxide (GO) films produces a significant change in the lattice structure of the material resulting in greater sp² hybridization and causes the precursor, GO, to become conductive. This technique has been exploited to design transparent, flexible electrode arrays for touch screen and supercapacitor applications promising a new, low-cost alternative to methods involving more expensive exotic compounds such as indium tin oxide (ITO). One challenge this process has faced is lower than expected conductivities, on the order of 10⁴ S/m, observed in the patterned material as compared to bulk graphite (10⁵ S/m) and epitaxially grown graphene (10⁸ S/m). We utilize carbon phase change data derived from annealing of natural carbon feed stocks to understand optimized conditions for patterning. We then show that these conditions produce electrode arrays of superior conductivity through laser patterning in a controlled atmosphere laser annealing chamber. Phase change data is also employed to relate graphene oxide to natural carbon feed stocks to demonstrate a proof of concept for low cost electronics.