Surface doping and bandgap tunability in hydrogenated graphene
A method of introducing a bandgap in single layer graphite on a SiO 2 substrate comprising the steps of preparing graphene flakes and CVD grown graphene films on a SiO 2 /Si substrate and performing hydrogenation of the graphene. Additionally, controlling the majority carrier type via surface adsorbates.
1. A method of introducing a bandgap in single layer graphene on a SiO 2 substrate comprising the steps of:
preparing graphene flakes or chemical vapor deposition grown graphene films on a SiO 2 /Si substrate;
exposing the graphene flakes or the chemical vapor deposition grown graphene film to hydrogen plasma;
performing hydrogenation of the graphene;
wherein the hydrogenated graphene has a majority carrier type;
creating a bandgap from the hydrogenation of the graphene;
applying an electric field to the hydrogenated graphene; and
tuning the bandgap.
2. The method of claim 1 further including the step of:
controlling the majority carrier type via surface adsorbates.
3. The method of claim 2 further comprising the steps of:
attaching by physisorption the surface adsorbates to the hydrogenated graphene;
converting the majority carrier type from electrons to holes using the surface adsorbates;
converting the majority carrier type from n-type to p-type;
removing the surface adsorbates;
preserving the hydrogenated graphene band structure; and
converting the majority carrier type from p-type to n-type.
4. A method of hydrogenating graphene and forming a bandgap comprising the steps of:
preparing exfoliated graphene flakes or a chemical vapor deposition (CVD) grown graphene film on a SiO 2 /Si substrate;
depositing contact electrodes on the exfoliated graphene flakes or the CVD grown graphene films;
exposing the exfoliated graphene flakes or the chemical vapor deposition grown graphene film to hydrogen plasma;
hydrogenating the exfoliated graphene flakes or the CVD grown graphene films;
creating a bandgap from the step of hydrogenating the graphene;
applying an electric field to the hydrogenated graphene; and
tuning the bandgap.
5. The method of claim 4 wherein the hydrogenating is performed with 15-30 W, 1.5 Torr H 2 , 100 sccm H 2 , 32 C, for 15-30 seconds.
6. The method of claim 5 wherein said contact electrodes are Cr/Au contact electrodes.