The effect of glass poling on graphene doping

Graphene combines a variety of unique properties, including mechanical robustness, transparency and high thermal and electrical conductivity, all together making it a promising material for a wide range of applications, such as exible displays, wearables and transparent electrodes. However, there are still many challenges preventing the implementation of this novel 2D material into devices. Most widely used fabrication techniques require a transfer step, to locate graphene on a substrate, which usually results in altered doping level of graphene, which degrades the electrical mobility of the material. So called electrostatic field tuning is the most used technique to tune the graphene doping. However, the method is limited by the charge that can be introduced in the material. This limitation depends on the dielectric constant of the layer that needs to be deposited: on top of the graphene (when the substrate is glass, "top-gating"), or below the graphene (when the substrate is Si, "back-gating"). In our case, as we work with glass, it would be very interesting to use the thermal poling to tune the graphene doping, as the limitation of the doping would be defined by the charges inside the glass. This post-processing technique is based on inducing an electric field inside the substrate, originating from the movement of ions when external voltage is applied at temperatures above 100 degrees Celsius. The intrinsic electric field remains when the external voltage is removed once that the glass has been cooled down to the room temperature