Improved inter-device variability in graphene liquid gate sensors by laser treatment

Abstract

We investigate the influence of a visible laser treatment on the electrical performance of CVD-grown graphene-based liquid gate sensors. This method allows us to treat locally the graphene sheet, improving the performance of the structure for biochemical sensing applications. It was found critical to control the atmosphere in which the laser treatment takes place. An optimized ambient-air laser exposure shifted the Dirac point (minimum of the conductivity voltage) around 300 mV to lower voltages, together with a decrease of the inter-device electrical variability. These results open the door to use the laser treatment to increase the sensibility and reproducibility of liquid gate graphene-based devices as sensors or biosensors.