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Bandstructure Manipulation of Epitaxial Graphene on SiC(0001) by Molecular Doping and Hydrogen Intercalation

Published online by Cambridge University Press:  01 February 2011

Ulrich Starke
Ulrich Starke*
Affiliation:
u.starke@fkf.mpg.de
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Abstract

Graphene, a monoatomic layer of graphite hosts a two-dimensional electron gas system with large electron mobilities which makes it a prospective candidate for future nanocarbon devices. Grown epitaxially on silicon carbide (SiC) wafers, large area graphene samples appear feasible and integration in existing device technology can be envisioned. A precise control of the number of graphene layers and growth of large homogeneous graphene samples can be achieved. However, as-grown epitaxial graphene on SiC is electron doped due to the influence of the reconstructed interface layer present between graphene and SiC. Covalent bonds between SiC and the first carbon layer grown on top induce a dipole layer which induces charges into the graphene. As a result, the Dirac point energy where the π-bands cross is shifted away from the Fermi energy, so that the ambipolar properties of graphene cannot be exploited. How this effect can be overcome by a precise control and manipulation of the electronic structure of the π-bands is demonstrated by two methods. On the one hand, transfer doping of the epitaxial graphene surfaces with the strong acceptor molecule tetrafluoro-tetracyanoquinodimethane (F4-TCNQ) allows for a fine tuning of the doping level. Charge neutrality can be achieved for mono- and bilayer graphene. On bilayer samples the magnitude of the existing bandgap can be increased up to more than double of its initial value. On the other hand, the impact of the SiC-graphene interface can be completely eliminated by annealing the samples in molecular hydrogen. The hydrogen atoms migrate through the graphene layers, intercalate between the SiC substrate and the interface layer and bind to the Si atoms of the SiC(0001) surface. Thus the interface layer, decoupled from the SiC substrate, is turned into a quasi-free standing graphene monolayer. Similarly, epitaxial monolayer graphene turns into a decoupled bilayer. The intercalation process represents a highly promising route towards epitaxial graphene based nanoelectronics.

Keywords

electronic structureintercalationcarbonization
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1246: Symposium B – Silicon Carbide 2010-Materials, Processing and Devices , 2010 , 1246-B10-01
Copyright
Copyright © Materials Research Society 2010

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References

1 Geim, A. K., and Novoselov, K. S., Nat. Mater. 6, 183 (2007).Google Scholar
2 Novoselov, K.S., Geim, A.K., Morosov, S.V., Jiang, D., Katsnelson, M.I., Grigorieva, I.V., Dubonos, S.V., and Firsov, A.A., Nature 438, 197 (2005).Google Scholar
3 Zhang, Y., Tan, Y. W., Stormer, H.L., and Kim, P., Nature 438, 201 (2005).Google Scholar
4 Navarro, C. Gomez, Burghard, M., and Kern, K., Nano Letters 8, 2045 (2008).Google Scholar
5 Geim, A.K., Science 324, 1530 (2009).Google Scholar
6 N'Diaye, A.T., Bleikamp, S., Feibelman, P.J., and Michely, T., Phys. Rev. Lett. 97, 215501 (2006).Google Scholar
7 Marchini, S., Günther, S., and Wintterlin, J., Phys. Rev. B 76, 075429 (2007).Google Scholar
8 Sutter, P.W., Flege, J. I., and Sutter, E.A., Nature Materials 7, 406 (2008).Google Scholar
9 Bommel, A.J. van, Crombeen, J.E., and van, A. Tooren, Surf. Sci. 48, 463 (1975).Google Scholar
10 Forbeaux, I., Themlin, J. M., and Debever, J. M., Phys. Rev. B 58, 16396 (1998).Google Scholar
11 Ohta, T., Bostwick, A., Seyller, Th., Horn, K., and Rotenberg, E., Science 313, 951 (2006).Google Scholar
12 Riedl, C., Starke, U., Bernhardt, J., Franke, M., and Heinz, K., Phys. Rev. B 76, 245406 (2007).Google Scholar
13 Starke, U., and Riedl, C., J. Phys.: CM 21, 134016 (2009).Google Scholar
14 Emtsev, K.V., Bostwick, A., Horn, K., Jobst, J., Kellogg, G.L., Ley, L., McChesney, J.L., Ohta, T., Reshanov, S.A., Rotenberg, E., Schmid, A.K., Waldmann, D., Weber, H.B., and Seyller, T., Nature Materials 8, 203–207 (2009).Google Scholar
15 Virojanadara, C., Syväjarvi, M., Yakimova, R., Johansson, L.I., Zakharov, A.A., and Balasubramanian, T., Phys. Rev. B 78, 245403 (2008).Google Scholar
16 Temimy, A. Al, Riedl, C., and Starke, U., Appl. Phys. Lett. 95, 231907 (2009).Google Scholar
17 Moreau, E., Ferrer, F.J., Vignaud, D., Godey, S., and Wallart, X., Phys. Status Solidi A 207, 300 (2010).Google Scholar
18 Riedl, C., Zakharov, A. A., and Starke, U.. Appl Phys. Lett. 93, 033106 (2008).Google Scholar
19 Gierz, I., Riedl, C., Starke, U., Ast, C.R., and Kern, K., Nano Lett. 8, 4603 (2008).Google Scholar
20 Coletti, C., Riedl, C., Lee, D. S., Krauss, B., Klitzing, K. v., Smet, J., and Starke, U., Phys. Rev. B, in press (arXiv:0909.2966).Google Scholar
21 Riedl, C., Coletti, C., Iwasaki, T., Zakharov, A.A., and Starke, U., Phys. Rev. Lett. 103, 246804 (2009).Google Scholar
22 , Soubatch, Saddow, S.E., Rao, S.P., Lee, W.Y., Konuma, M., and Starke, U., Mat. Sci. Forum 483–485, 761 (2005).Google Scholar
23 Frewin, L., Coletti, C., Riedl, C., Starke, U., and Saddow, S.E., Mat. Sci. Forum 615–617, 589 (2009).Google Scholar
24 Tsuchida, H., Kamata, I., and Izumi, K., J. Appl. Phys. 85, 3569 (1999).Google Scholar
25 Seyller, T., J. Phys. CM 16, S1755 (2004).Google Scholar
26 Coletti, C., Frewin, C.L., Hoff, A.M., and Saddow, S.E., Electrochem. Solid State Lett. 11, H285 (2008).Google Scholar
27 Patthey, L., Schmidt, T., Flechsig, U., Quitmann, C., Shi, M., Betemps, R., Botkine, M., Abela, R., in PSI Scientic Report 1999/Volume VII, Surface/Interface Spectroscopy Beamline (Paul Scherrer Institut, 2002).Google Scholar
28 Nyholm, R., Andersen, J.N., Johansson, U., Jensen, B.N., and Lindau, I., Nucl. Instr. and Meth. in Phys. Res. A 467–468, 520 (2001).Google Scholar
29 Emtsev, K.V., Speck, F., Seyller, T., Ley, L., and Riley, J.D., Phys. Rev. B 77, 155303 (2008).Google Scholar
30 Bostwick, A., Ohta, T., McChesney, J.L., Emtsev, K.V, Seyller, T., Horn, K., and Rotenberg, E., New J. Phys. 9, 385 (2007).Google Scholar
31 Ohta, T., Bostwick, A., McChesney, J.L., Seyller, T., Horn, K., and Rotenberg, E., Phys. Rev. Lett. 98, 206802 (2007).Google Scholar
32 Zhou, S.Y., Gweon, G. H., Fedorov, A.V., First, P.N., Heer, W.A. de, Lee, D. H., Guinea, F., Neto, A.H. Castro, and Lanzara, A., Nature Materials 6, 770 (2007).Google Scholar
33 Bostwick, A., Ohta, T., Seyller, T., Horn, K., and Rotenberg, E., Nature Physics 3, 36 (2007).Google Scholar
34 Wells, S.K., Giergel, J., Land, T.A., Lindquist, J.M., and Hemminger, J.C., Surf. Sci. 257, 129 (1991).Google Scholar
35 Chen, W., Chen, S., Qui, D.C., Gao, X.Y., and Wee, A.T.S., J. Am. Chem. Soc. 129, 10418 (2007).Google Scholar
36 Lindquist, J.M., and Hemminger, J.C., J. Phys. Chem. 92, 1394 (1998).Google Scholar
37 Romaner, L., Heimel, G., Bredas, J. L., Gerlach, A., Schreiber, F., Johnson, R.L., Zegenhagen, J., Duhm, S., Koch, N., and Zojer, E., Phys. Rev. Lett. 99, 256801 (2007).Google Scholar
38 Qi, D., Chen, W., Gao, X., Wang, L., Chen, S., Loh, K.P., and Wee, A.T.S., J. Amer. Chem. Soc. 129, 8084 (2007).Google Scholar
39 McCann, E., and Fal'ko, V.I., Phys. Rev. Lett. 96, 086805 (2006).Google Scholar
40 Forti, S., Riedl, C., Coletti, C., Emtsev, K.V., Zakharov, A.A., and Starke, U., unpublished.Google Scholar
41 Hibino, H., Kageshima, H., Maeda, F., Nagase, M., Kobayashi, Y., and Yamaguchi, H., Phys. Rev. B 77, 075413 (2008).Google Scholar