Transfer characteristics in graphene field-effect transistors with Co contacts

Graphene field-effect transistors with Co contacts as source and drain electrodes show anomalous distorted transfer characteristics. The anomaly appears only in short-channel devices (shorter than approximately 3 μm) and originates from a contact-induced effect. Band alteration of a graphene channel by the contacts is discussed as a possible mechanism for the anomalous characteristics observed.

[1]  Michael S. Fuhrer,et al.  Gate-tunable graphene spin valve , 2007 .

[2]  S. Marchini,et al.  Scanning tunneling microscopy of graphene on Ru(0001) , 2007 .

[3]  C. Oshima,et al.  REVIEW ARTICLE: Ultra-thin epitaxial films of graphite and hexagonal boron nitride on solid surfaces , 1997 .

[4]  J. Brink,et al.  Doping graphene with metal contacts. , 2008, Physical review letters.

[5]  A. Geim,et al.  Two-dimensional gas of massless Dirac fermions in graphene , 2005, Nature.

[6]  Vladimir I. Fal'ko,et al.  Selective transmission of Dirac electrons and ballistic magnetoresistance of n − p junctions in graphene , 2006 .

[7]  Andre K. Geim,et al.  The rise of graphene. , 2007, Nature materials.

[8]  H. Okada,et al.  High-quality and highly oriented graphite block from polycondensation polymer films , 1992 .

[9]  Andre K. Geim,et al.  Two-dimensional atomic crystals. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[10]  A. Alivisatos,et al.  Electrical contacts to individual colloidal semiconductor nanorods. , 2008, Nano letters.

[11]  Masashi Shiraishi,et al.  Spin injection into a graphene thin film at room temperature , 2007 .

[12]  Vladimir Fal'ko,et al.  The Focusing of Electron Flow and a Veselago Lens in Graphene p-n Junctions , 2007, Science.

[13]  P. Kim,et al.  Experimental observation of the quantum Hall effect and Berry's phase in graphene , 2005, Nature.

[14]  H. Michaelson.  The work function of the elements and its periodicity , 1977 .

[15]  G. Fudenberg,et al.  Ultrahigh electron mobility in suspended graphene , 2008, 0802.2389.

[16]  B. Wees,et al.  Electronic spin transport and spin precession in single graphene layers at room temperature , 2007, Nature.

[17]  L. Vandersypen,et al.  Gate-induced insulating state in bilayer graphene devices. , 2007, Nature materials.

[18]  M. Tsukada,et al.  Electronic states and scanning tunneling spectroscopy image of monolayer graphite on a nickel (111) surface by the DV-Xα method , 1995 .

[19]  D. Goldhaber-Gordon,et al.  Evidence of the role of contacts on the observed electron-hole asymmetry in graphene , 2008, 0804.2040.

[20]  D. Goldhaber-Gordon,et al.  Transport measurements across a tunable potential barrier in graphene. , 2007, Physical review letters.