We report new Raman features of epitaxial graphene (EG) on Si-face 4H-SiC prepared by pulsed electron irradiation (PEI). With increasing graphene layers, frequencies of G and 2D peaks show blue-shifts and approach those of bulk highly-oriented pyrolytic graphite. It is indicated that the EG is slightly tension strained and tends to be strain-free. Meanwhile, single Lorentzian line shapes are well fitted to the 2D peaks of EG on SiC(0001) and their full widths at half maximum decrease with the increasing graphene layers, which indicates that the multilayer EG on Si-face can also contain turbostratic stacking by our PEI route instead of only AB Bernal stacking by a traditional thermal annealing method. It is worth noting that the stacking style plays an important role on the charge carrier mobility. Therefore our findings will be a candidate for growing quality graphene with high carrier mobility both on the Si- and C-terminated SiC substrate. Mechanisms behind the features are studied and discussed.
We report new Raman features of epitaxial graphene (EG) on Si-face 4H-SiC prepared by pulsed electron irradiation (PEI). With increasing graphene layers, frequencies of G and 2D peaks show blue-shifts and approach those of bulk highly-oriented pyrolytic graphite. It is indicated that the EG is slightly tension strained and tends to be strain-free. Meanwhile, single Lorentzian line shapes are well fitted to the 2D peaks of EG on SiC(0001) and their full widths at half maximum decrease with the increasing graphene layers, which indicates that the multilayer EG on Si-face can also contain turbostratic stacking by our PEI route instead of only AB Bernal stacking by a traditional thermal annealing method. It is worth noting that the stacking style plays an important role on the charge carrier mobility. Therefore our findings will be a candidate for growing quality graphene with high carrier mobility both on the Si- and C-terminated SiC substrate. Mechanisms behind the features are studied and discussed.
HUANG Qing-Song;GUO Li-Wei;WANG Wen-Jun;WANG Gang;WANG Wan-Yan;JIA Yu-Ping;LIN Jing -Jing;LI Kang;CHEN Xiao-Long. Raman Spectrum of Epitaxial Graphene on SiC (0001) by Pulsed Electron Irradiation[J]. 中国物理快报, 2010, 27(4): 46803-046803.
HUANG Qing-Song, GUO Li-Wei, WANG Wen-Jun, WANG Gang, WANG Wan-Yan, JIA Yu-Ping, LIN Jing -Jing, LI Kang, CHEN Xiao-Long. Raman Spectrum of Epitaxial Graphene on SiC (0001) by Pulsed Electron Irradiation. Chin. Phys. Lett., 2010, 27(4): 46803-046803.
[1] Novoselov K S, Geim A K et al 2004 Science 306 666 [2] Novoselov K S, Geim A K, Morozov S V, Jiang D, Katsnelson M I, Grigorieva I V et al 2005 Nature 438 197 [3] Ferralis N, Maboudian R and Carraro C 2008 Phys. Rev. Lett. 101 156801 [4] Pan Y, Zhang H, Shi D, Sun J, Du S, Liu F and Gao H J 2009 Adv. Mater. 21 2777 [5] Li X, Cai W, An J, Kim S, Nah J, Yang D, Piner R, Velamakanni A, Jung I, Tutuc E et al 2009 Science 324 1312 [6] Stoberl U, Wurstbauer U, Wegscheider W, Weiss D and Eroms J 2008 Appl. Phys. Lett. 93 051906 [7] Geim A K and Novoselov K S 2007 Nat.Mater. 6 183 [8] Hass J, Feng Li R T, Li X, Zong Z, de Heer W A, First P N, Conrad E H et al 2006 Appl. Phys. Lett. 89 143106 [9] Ni Z H, Chen W, Fan X F, Kuo J L, Yu T, Wee A T S and Shen Z X 2008 Phys. Rev. B 77 115416 [10] Röhrl J, Hundhausen M, Emtsev K V, Seyller Th, Graupner R and Ley L 2008 Appl. Phys. Lett. 92 201918 [11] Hass J, de Heer W A and Conrad E H 2008 J. Phys.: Condens. Matter 20 323202 [12] Lin Y M, Jenkins A K, Garcia A, Small V J P, Farmer D B and Avouris P 2009 Nano Lett. 9 422 [13] Malard L M, Pimenta M A, Dresselhaus G and Dresselhaus M S 2009 Phys. Rep. 473 51 [14] Lee D S, Riedl C, Krauss B, von Klitzing K, Starke U and Smet J H 2008 Nano Lett. 8 4320 [15] Hallin C, Owman F, Mårtensson P, Ellison A, Konstantinov A et al 1997 J. Crys. Growth 181 241 [16] Tuinstar F and Koenig J L 1970 J. Chem. Phys. 53 1126 [17] Thomsen C and Reich S 2000 Phys. Rev. Lett. 85 5214 [18] Ferrari A C, Meyer J C, Scardaci V, Casiraghi C, Lazzeri M, Mauri F et al 2006 Phys. Rev. Lett. 97 187401 [19] Faugeras C, Nerriére A, Potemski M, Mahmood A, Dujardin E, Berger C and de Heer W A 2008 Appl. Phys. Lett. 92 011914 [20] Emtsev K V, Speck F, Seyller Th and Ley L 2008 Phys. Rev. B 77 155303 [21] Shaffer P T B 1969 Acta Cryst. B 25 477 [22] Graf D, Molitor F, Ensslin K, Stampfer C, Jungen A, Hierold C and Wirtlz L 2007 Nano Lett. 7 238 [23] Das A, Pisana S, Chakraborty B, Piscanec S, Saha S, Waghmare K U V et al 2008 Nature Nanotechnol. 3 210 [24] Robinson J A, Puls C P, Staley N E, Stitt J P, Fanton M A, Emtsev K V et al 2009 Nano Lett. 9 964 [25] Latil S, Meunier V and Henrard L 2007 Phys. Rev. B 76 201402 [26] Robinson J A, Wetherington M, Tedesco J L, Campbell P M, Weng X J et al 2009 Nano Lett. 9 2873
2010, Vol. 27 
