A graphene sample was prepared onto the glass Pyrex substrate using the process described in the reference [11]. The
sample preparation was inspired from the anodic bonding that is usually used to bond Si to a Pyrex substrate. Very firm
contact is obtained between the substrate and Si allowed by the formation of chemical bonds at the interface by an application of a potential difference on the order of a kV to the heated Pyrex/Si substrate. The principle of anodic bonding in Si/Pyrex can further be referred from the