Share This Article:

Na Induced Changes in the Electronic Band Structure of Graphene Grown on C-Face SiC

Full-Text HTML Download Download as PDF (Size:642KB) PP. 1-7
DOI: 10.4236/graphene.2013.21001    3,468 Downloads   6,518 Views   Citations

ABSTRACT

Studies of the effects induced on the electron band structure after Na deposition, and subsequent heating, on a C-face 2 MLs graphene sample are reported. Na deposition shifts the Dirac point downwards from the Fermi level by about 0.5 eV due to electron doping. After heating at temperatures from around 120℃ to 300℃,thep-band appears considerably broadened. Collected Si 2p and Na 2p spectra then indicate Na intercalation in between the graphene layers and at the graphene SiC interface. The broadening is therefore interpreted to arise from the presence of two slightly shifted, but not clearly resolved,p-bands. Constant energy photoelectron distribution patterns, E(kx,ky);s, extracted from the clean 2MLs graphene C-face sample look very similar to earlier calculated distribution patterns for monolayer, but not Bernal stacked bilayer, graphene. After Na deposition the patterns extracted at energies below the Dirac point appear very similar so the doping had no pronounced effect on the shape or intensity distribution. At energies above the Dirac point the extracted angular distribution patterns show the flipped, “mirrored”, intensity distribution predicted for monolayer graphene at these energies. An additional weaker outer band is also discernable at energies above the Dirac point, which presumably is induced by the deposited Na.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

L. Johansson, C. Xia and C. Virojanadara, "Na Induced Changes in the Electronic Band Structure of Graphene Grown on C-Face SiC," Graphene, Vol. 2 No. 1, 2013, pp. 1-7. doi: 10.4236/graphene.2013.21001.

References

[1] P. N. First, W. A. de Heer, T. Seyller, C. Berger, J. A. Stroscio and J.-S. Moon, “Epitaxial Graphenes on Silicon Carbide,” MRS Bulletin, Vol. 35, No. 4, 2010, pp. 296- 305. doi:10.1557/mrs2010.552
[2] M. S. Dresselhaus and G. Dresselhaus, “Intercalation Compounds of Graphite,” Advances in Physics, Vol. 51, No. 1, 2002, pp. 1-186. doi:10.1080/00018730110113644
[3] S. Watcharinyanon, L. I. Johansson, C. Xia and C. Viro- janadara, “Changes in Structural and Electronic Proper- ties of Graphene Grown on 6H-SiC(0001) Induced by Na Deposition,” Journal of Applied Physics, Vol. 111, No. 8, 2012, Article ID: 083711. doi:10.1063/1.4704396
[4] A. Sandin, T. Jayasekera, J. E. Rowe, K. W. Kim, M. B. Nardelli and D. B. Dougherty, “Multiple Coexisting In- tercalation Structures of Sodium in Epitaxial Graphene- SiC Interfaces,” Physical Review B, Vol. 85, 2012, Arti- cle ID: 125410. doi:10.1103/PhysRevB.85.125410
[5] C. Xia, S. Watcharinyanon, A. A. Zakharov, L. I. Johans- son, R. Yakimova and C. Virojanadara, “Detailed Studies of Na Intercalation on Furnace-Grown Graphene on 6H- SiC(0001),” in Press.
[6] T. Ohta, A. Bostwick, J. L. Mc-Chesney, T. Seyller, K. Horn and E. Rotenberg, “Interlayer Interaction and Elec- tronic Screening in Multilayer Graphene Investigated with Angle-Resolved Photoemission Spectroscopy,” Physical Review Letters, Vol. 98, No. 20, 2007, Article ID: 206802. doi:10.1103/PhysRevLett.98.206802
[7] A. Bostwick, T. Ohta, T. Seyller, K. Horn and E. Roten- berg, “Quasiparticle Dynamics in Graphen,” Nature Phys- ics, Vol. 3, 2007, pp. 36-40. doi:10.1038/nphys477
[8] A. A. Bostwick, F. Speck, T. Seyller, K. Horn, M. Polini, R. Asgari, A. H. MacDonald and E. Rotenberg, “Obser- vation of Plasmarons in Quasi-Freestanding Doped Gra- phene,” Science, Vol. 328, No. 5981, 2010, pp. 999-1002. doi:10.1126/science.1186489
[9] C. Virojanadara, S. Watcharinyanon, A. A. Zakharov and L. I. Johansson, “Epitaxial Graphene on 6H-SiC and Li Intercalation,” Physical Review B, Vol. 82, No. 20, 2010, Article ID: 205402. doi:10.1103/PhysRevB.82.205402
[10] S. Watcharinyanon, C. Virojanadara and L. I. Johansson, “Rb and Cs Deposition on Epitaxial Graphene Grown on 6H-SiC(0001),” Surface Science, Vol. 605, No. 21-22, 2011, pp. 1918-1922. doi:10.1016/j.susc.2011.07.007
[11] A.L. Walter, A. Bostwick, K.-J. Jeon, F. Speck, M. Ostler, T. Seyller, L. Moreschini, Y.J. Chang, M. Polini, R. Asgari, A.H. MacDonald, K. Horn, E. Rotenberg,” Effective screening and the plasmaron bands in graphene,“ Physical Review B, Vol. 84, No. 8, 2011, Article ID: 085410. doi:10.1103/PhysRevB.84.085410
[12] M. Sprinkle, D. Siegel, Y. Hu, J. Hicks, A. Tejeda, A. Taleb-Ibrahimi, P. Le Fe’vre, F. Bertran, S. Vizzini, H. Enriquez, S. Chiang, P. Soukiassian, C. Berger, W. A. de Heer, A. Lanzara and E. H. Conrad, “First Direct Obser- vation of a Nearly Ideal Graphene Band Structure,” Phy- sical Review Letters, Vol. 103, No. 22, 2009, Article ID: 226803. doi:10.1103/PhysRevLett.103.226803
[13] D. A. Siegel, C. G. Hwang, A. W. Fedorov and A. Lanzara, “Quasifreestanding Multilayer Graphene Films on the Carbon Face of SiC,” Physical Review B, Vol. 81, No. 24, 2010, Article ID: 241417. doi:10.1103/PhysRevB.81.241417
[14] L. I. Johansson, S. Watcharinyanon, A. A. Zakharov, T. Iakimo, R. Yakimova and C. Virojanadara, “Stacking of Adjacent Graphene Layers Grown on C-Face SiC,” Phy- sical Review B, Vol. 84, No. 12, 2011, Article ID: 125405. doi:10.1103/PhysRevB.84.125405
[15] S. Latil, V. Meunier and L. Henrard, “Massless Fermions in Multilayer Graphitic Systems with Misoriented Layers: Ab Initio Calculations and Experimental Fingerprints,” Physical Review B, Vol. 76, No. 20, 2007, Article ID: 201402. doi:10.1103/PhysRevB.76.201402
[16] S. Latil and L. Henrard, “Charge Carriers in Few-Layer Graphene Films,” Physical Review Letters, Vol. 97, No. 3, 2006, Article ID: 036803. doi:10.1103/PhysRevLett.97.036803
[17] J. Hass, R. Feng, J. E. Millan-Otoya, X. Li, M. Sprinkle, P. N. First, W. A. de Heer, E. H. Conrad and C. Berger, “Structural Properties of the Multilayer Graphene/4H-Si (000-1) System as Determined by Surface X-Ray Diffrac- tion,” Physical Review B, Vol. 75, No. 21, 2007, Article ID: 214109. doi:10.1103/PhysRevB.75.214109
[18] K. V. Emtsev, F. Speck, Th. Seyller, L. Ley and J. D. Riley, “Interaction, Growth, and Ordering of Epitaxial Graphene on SiC{0001} Surfaces: A Comparative Photoelectron Spectroscopy Study,” Physical Review B, Vol. 77, No. 15, 2008, Article ID: 155303. doi:10.1103/PhysRevB.77.155303
[19] M. Mucha-Kruczyński, O. Tsyplyatyev, A. Grishin, E. McCann, Vladimir I. Fal’ko, A. Bostwick and E. Roten- berg, “Characterization of Graphene through Anisotropy of Constant-Energy Maps in Angle-Resolved Photoemis- sion,” Physical Review B, Vol. 77, No. 19, 2008, Article ID: 195403. doi:10.1103/PhysRevB.77.195403
[20] I. Gierz, J. Henk, H. H?chst, C. R. Ast and K. Kern, “Il- luminating the Dark Corridor in Graphene: Polarization Dependence of Angle-Resolved Photoemission Spectro- scopy on Graphene,” Physical Review B, Vol. 83, No. 12, 2011, Article ID: 121408. doi:10.1103/PhysRevB.83.121408

  
comments powered by Disqus

Copyright © 2018 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.