Atomically resolved electronic properties in single layer graphene on α-Al2O3 (0001) by chemical vapor deposition

Scientific Reports, vol. 12, pp. 18743

Abstract

Abstract Metal-free chemical vapor deposition (CVD) of single-layer graphene (SLG) on c-plane sapphire has recently been demonstrated for wafer diameters of up to 300 mm, and the high quality of the SLG layers is generally characterized by integral methods. By applying a comprehensive analysis approach, distinct interactions at the graphene-sapphire interface and local variations caused by the substrate topography are revealed. Regions near the sapphire step edges show tiny wrinkles with a height of about 0.2 nm, framed by delaminated graphene as identified by the typical Dirac cone of free graphene. In contrast, adsorption of CVD SLG on the hydroxyl-terminated α-Al2O3 (0001) terraces results in a superstructure with a periodicity of (2.66 ± 0.03) nm. Weak hydrogen bonds formed between the hydroxylated sapphire surface and the π-electron system of SLG result in a clean interface. The charge injection induces a band gap in the adsorbed graphene layer of about (73 ± 3) meV at the Dirac point. The good agreement with the predictions of a theoretical analysis underlines the potential of this hybrid system for emerging electronic applications.

Authors 10

1. Henrik Wördenweber Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Peter Grünberg Institute 7, Forschungszentrum Jülich GmbH and JARA-FIT, 52425, Jülich, Germany

   RWTH Aachen University, 52066, Aachen, Germany

2. Silvia Karthäuser corresponding

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Peter Grünberg Institute 7, Forschungszentrum Jülich GmbH and JARA-FIT, 52425, Jülich, Germany. s.karthaeuser@fz-juelich.de

   Peter Grünberg Institute 7, Forschungszentrum Jülich GmbH and JARA-FIT, 52425, Jülich, Germany

3. Annika Grundmann Aachen Compound Semiconductor Technology

   RWTH Aachen University

   Affiliation as printed

   Compound Semiconductor Technology, RWTH Aachen University, 52074, Aachen, Germany

4. Zhaodong Wang Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Peter Grünberg Institute 7, Forschungszentrum Jülich GmbH and JARA-FIT, 52425, Jülich, Germany

   RWTH Aachen University, 52066, Aachen, Germany

5. Stephan Aussen Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Peter Grünberg Institute 7, Forschungszentrum Jülich GmbH and JARA-FIT, 52425, Jülich, Germany

   RWTH Aachen University, 52066, Aachen, Germany

6. H. Kalisch Aachen Compound Semiconductor Technology

   RWTH Aachen University

   Affiliation as printed

   Compound Semiconductor Technology, RWTH Aachen University, 52074, Aachen, Germany

7. Andrei Vescan Aachen Compound Semiconductor Technology

   RWTH Aachen University

   Affiliation as printed

   Compound Semiconductor Technology, RWTH Aachen University, 52074, Aachen, Germany

8. M. Heuken Aachen Compound Semiconductor Technology

   Aixtron (Germany) · RWTH Aachen University

   Affiliation as printed

   AIXTRON SE, 52134, Herzogenrath, Germany

   Compound Semiconductor Technology, RWTH Aachen University, 52074, Aachen, Germany

9. Rainer M. Waser Aachen Institute of Materials in Electrical Engineering and Information Technology II

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering and Information Technology II, RWTH Aachen University, 52074, Aachen, Germany

   JARA-Institute Energy-Efficient Information Technology (Green IT & PGI-10), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany

   Peter Grünberg Institute 7, Forschungszentrum Jülich GmbH and JARA-FIT, 52425, Jülich, Germany

10. Susanne Hoffmann‐Eifert corresponding

    Forschungszentrum Jülich · Jülich Aachen Research Alliance

    Affiliation as printed

    JARA-Institute Energy-Efficient Information Technology (Green IT & PGI-10), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany. su.hoffmann@fz-juelich.de

    JARA-Institute Energy-Efficient Information Technology (Green IT & PGI-10), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany