Improved moisture stability of graphene transistors by controlling water molecule adsorption

Although atomically thin two-dimensional graphene is of interest for next-generation electronic device applications owing to its outstanding properties, a crucial issue concerning the stable operation of graphene-based devices under ambient conditions still remains for industrial applications. Because the electrical performance of graphene-based devices is largely affected by polar atmospheric species such as water molecules (H₂O), it is important to eliminate this detrimental effect. In the present study, we report a facile method to enhance the moisture stability of graphene field-effect transistors (FETs) by modulating the surface energy of substrates. We found that this simple method enables us not only to retain the way to secure field-effect mobility, but also to improve the stability of graphene FETs. The device on the surface-modulated substrates showed excellent moisture stability, even under harsh humid environments. We expect that the proposed method will be widely useful for the improvement of ambient stability in various 2D material-based electronics.