Skip to main content
Log in

Effect of electron injection in copper-contacted graphene nanoribbons

  • Research Article
  • Published:
Nano Research Aims and scope Submit manuscript

Abstract

For practical electronic device applications of graphene nanoribbons (GNRs), it is essential to have abrupt and well-defined contacts between the ribbon and the adjacent metal lead. By analogy with graphene, these contacts can induce electron or hole doping, which may significantly affect the I/V characteristics of the device. Cu is among the most popular metals of choice for contact materials. In this study, we investigate the effect of in situ intercalation of Cu on the electronic structure of atomically precise, spatially aligned armchair GNRs of width N = 7 (7-AGNRs) fabricated via a bottom-up method on the Au(788) surface. Scanning tunneling microscopy data reveal that the complete intercalation of about one monolayer of Cu under 7-AGNRs can be facilitated by gentle annealing of the sample at 80 °C. Angle-resolved photoemission spectroscopy (ARPES) data clearly reflect the one-dimensional character of the 7-AGNR band dispersion before and after intercalation. Moreover, ARPES and core-level photoemission results show that intercalation of Cu leads to significant electron injection into the nanoribbons, which causes a pronounced downshift of the valence and conduction bands of the GNR with respect to the Fermi energy (ΔE ~ 0.5 eV). As demonstrated by ARPES and X-ray absorption spectroscopy measurements, the effect of Cu intercalation is restricted to n-doping only, without considerable modification of the band structure of the GNRs. Post-annealing of the 7-AGNRs/Cu/Au(788) system at 200 °C activates the diffusion of Cu into Au and the formation of a Cu-rich surface Au layer. Alloying of intercalated Cu leads to the recovery of the initial position of GNR-related bands with respect to the Fermi energy (E F), thus, proving the tunability of the induced n-doping.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Geim, A. K.; Novoselov, K. S. The rise of graphene. Nat. Mater. 2007, 6, 183–191.

    Article  Google Scholar 

  2. Schwierz, F. Graphene transistors. Nat. Nanotechnol. 2010, 5, 487–496.

    Article  Google Scholar 

  3. Novoselov, K. S.; Fal’ko, V. I.; Colombo, L.; Gellert, P. R.; Schwab, M. G.; Kim, K. A roadmap for graphene. Nature 2012, 490, 192–200.

    Article  Google Scholar 

  4. Lin, Y. M.; Dimitrakopoulos, C.; Jenkins, K. A.; Farmer, D. B.; Chiu, H. Y.; Grill, A.; Avouris, P. 100-GHz transistors from wafer-scale epitaxial graphene. Science 2010, 327, 662–662.

    Article  Google Scholar 

  5. Nakada, K.; Fujita, M.; Dresselhaus, G.; Dresselhaus, M. S. Edge state in graphene ribbons: Nanometer size effect and edge shape dependence. Phys. Rev. B 1996, 54, 17954–17961.

    Article  Google Scholar 

  6. Son, Y.-W.; Cohen, M. L.; Louie, S. G. Half-metallic graphene nanoribbons. Nature 2006, 444, 347–349.

    Article  Google Scholar 

  7. Yang, L.; Park, C.-H.; Son, Y.-W.; Cohen, M. L.; Louie, S. G. Quasiparticle energies and band gaps in graphene nanoribbons. Phys. Rev. Lett. 2007, 99, 186801.

    Article  Google Scholar 

  8. Shemella, P.; Zhang, Y. M.; Mailman, M.; Ajayan, P. M.; Nayak, S. K. Energy gaps in zero-dimensional graphene nanoribbons. Appl. Phys. Lett. 2007, 91, 042101.

    Article  Google Scholar 

  9. Nguyen, L. T.; Pham, C. H.; Nguyen, V. L. Electronic band structures of graphene nanoribbons with self-passivating edge reconstructions. J. Phys.: Condens. Mat. 2011, 23, 295503.

    Google Scholar 

  10. Han, M. Y.; Özyilmaz, B.; Zhang, Y. B.; Kim, P. Energy band-gap engineering of graphene nanoribbons. Phys. Rev. Lett. 2007, 98, 206805.

    Article  Google Scholar 

  11. Bai, J. W.; Huang, Y. Fabrication and electrical properties of graphene nanoribbons. Mater. Sci. Eng. R 2010, 70, 341–353.

    Article  Google Scholar 

  12. Yazyev, O. V. A guide to the design of electronic properties of graphene nanoribbons. Acc. Chem. Res. 2013, 46, 2319–2328.

    Article  Google Scholar 

  13. Cai, J. M.; Ruffieux, P.; Jaffar, R.; Bieri, M.; Braun, T.; Blankenburg, S.; Muoth, M.; Seitsonen A. P.; Saleh, M.; Feng, X. L. et al. Atomically precise bottom-up fabrication of graphene nanoribbons. Nature 2010, 466, 470–473.

    Article  Google Scholar 

  14. Talirz, L.; Söde, H.; Cai, J. M.; Ruffieux, P.; Blankenburg, S.; Jaffar, R.; Berger, R.; Feng, X. L.; Müllen, K.; Passerone, D. et al. Termini of bottom-up fabricated graphene nanoribbons. J. Am. Chem. Soc. 2013, 135, 2060–2063.

    Article  Google Scholar 

  15. Van der Lit, J.; Boneschanscher, M. P.; Vanmaekelbergh, D.; Ijäs, M; Uppstu, A; Ervasti, M; Harju; A.; Liljeroth, P.; Swart, I. Suppression of electron–vibron coupling in graphene nanoribbons contacted via a single atom. Nat. Commun. 2013, 4, 2023.

    Google Scholar 

  16. Chen, Y.-C.; de Oteyza, D. G.; Pedramarzi, Z.; Chen, C.; Ficher, F. R.; Crommie, M. F. Tuning the band gap of graphene nanoribbons synthesized from molecular precursors. ACS Nano 2013, 7, 6123–6128.

    Article  Google Scholar 

  17. Cai, J. M.; Pignedoli, C. A.; Talirz, L.; Ruffieux, P.; Söde, H.; Liang, L. B.; Meunier, V.; Berger, R.; Li, R. J.; Feng, X. L. et al. Graphene nanoribbon heterojunctions. Nat. Nanotechnol. 2014, 9, 896–900.

    Article  Google Scholar 

  18. Bronner, C., Björk, J., Tegeder, P. Tracking and removing Br during the on-surface synthesis of a graphene nanoribbon. J. Phys. Chem. C. 2015, 119, 486–493.

    Article  Google Scholar 

  19. Chen, Y. C.; Cao, T.; Chen, C.; Pedramrazi, Z.; Haberer, D.; de Oteyza, D. G.; Fischer, F. R.; Louie, S. G.; Crommie, M. F. Molecular bandgap engineering of bottom-up synthesized graphene nanoribbon heterojunctions. Nat. Nanotechnol. 2015, 10, 156–160.

    Article  Google Scholar 

  20. Basagni, A.; Sedona, F.; Pignedoli, C. A.; Cattelan, M.; Nicolas, L.; Casarin, M.; Sambi, M. Molecules-oligomersnanowires-graphene nanoribbons: A bottom-up stepwise on-surface covalent synthesis preserving long-range order. J. Am. Chem. Soc. 2015, 137, 1802–1808.

    Article  Google Scholar 

  21. Zhang, H. M.; Lin, H. P.; Sun, K. W.; Chen, L.; Zagranyarski, Y.; Aghdassi, N.; Duhm,, S.; Li, Q.; Zhong, D. Y.; Li, Y. Y. et al. On-surface synthesis of rylene-type graphene nanoribbons. J. Am. Chem. Soc. 2015, 137, 4022–4025.

    Article  Google Scholar 

  22. Kimouche, A.; Ervasti, M. M.; Drost, R.; Halonen, S.; Harju, A.; Joensuu, P. M.; Sainio, J.; Liljeroth, P. Ultra-narrow metallic armchair graphene nanoribbons. Nat. Commun. 2015, 6, 10177.

    Article  Google Scholar 

  23. Simonov, K. A.; Vinogradov, N. A.; Vinogradov, A. S.; Generalov, A. V.; Zagrebina, E. M.; Mårtensson, N.; Cafolla, A. A.; Carpy, T.; Cunniffe, J. P.; Preobrajenski, A. B. Effect of substrate chemistry on the bottom-up fabrication of graphene nanoribbons: Combined core-level spectroscopy and STM study. J. Phys. Chem. C 2014, 118, 12532–12540.

    Article  Google Scholar 

  24. Söde, H.; Talirz, L.; Gröning, O.; Pignedoli, C. A.; Berger, R.; Feng, X. L.; Müllen, K.; Fasel, R; Ruffieux, P. Electronic band dispersion of graphene nanoribbons via Fouriertransformed scanning tunneling spectroscopy. Phys. Rev. B 2015, 91, 045429.

    Article  Google Scholar 

  25. Massimi, L.; Ourdjini, O.; Lafferentz, L.; Koch, M.; Grill, L.; Cavaliere, E.; Gavioli, L.; Cardoso, C.; Prezzi, D.; Molinari, E. et al. Surface-assisted reactions toward formation of graphene nanoribbons on Au(110) surface. J. Phys. Chem. C 2015, 119, 2427–2437.

    Google Scholar 

  26. Ruffieux, P.; Cai, J. M.; Plumb, N. C.; Patthey, L.; Prezzi, D.; Ferretti, A.; Molinari, E.; Feng, X. L.; Müllen, K.; Pignedoli, C. A. et al. Electronic structure of atomically precise graphene nanoribbons. ACS Nano 2012, 6, 6930–6935.

    Article  Google Scholar 

  27. Linden, S.; Zhong, D.; Timmer, A.; Aghdassi, N.; Franke, J. H.; Zhang, H.; Feng, X.; Müllen, K.; Fuchs, H.; Chi, L. et al. Electronic structure of spatially aligned graphene nanoribbons on Au(788). Phys. Rev. Lett. 2012, 108, 216801.

    Article  Google Scholar 

  28. Huang, H.; Wei, D. C.; Sun, J. T.; Wong, S. L.; Feng, Y. P.; Neto, A. H. C.; Wee, A. T. S. Spatially resolved electronic structures of atomically precise armchair graphene nanoribbons. Sci. Rep. 2012, 2, 983.

    Google Scholar 

  29. Han, P.; Akagi, K.; Canova, F. F.; Mutoh, H.; Shiraki, S.; Iwaya, K.; Weiss, P. S.; Asao, N.; Hitosugi, T. Bottom-up graphene-nanoribbon fabrication reveals chiral edges and enantioselectivity. ACS Nano 2014, 8, 9181–9187.

    Article  Google Scholar 

  30. Simonov, K. A.; Vinogradov, N. A.; Vinogradov, A. S.; Generalov, A. V.; Zagrebina, E. M.; Mårtensson, N.; Cafolla, A. A.; Carpy, T.; Cunniffe, J. P.; Preobrajenski, A. B. Comment on “Bottom-up graphene-nanoribbon fabrication reveals chiral edges and enantioselectivity”. ACS Nano 2015, 9, 3399–3403.

    Article  Google Scholar 

  31. Simonov, K. A.; Vinogradov, N. A.; Vinogradov, A. S.; Generalov, A. V.; Zagrebina, E. M.; Svirskiy, G. I.; Cafolla, A. A.; Carpy, T.; Cunniffe, J. P.; Taketsugu, T. et al. From graphene nanoribbons on Cu(111) to nanographene on Cu(110): Critical role of substrate structure in the bottom-up fabrication strategy. ACS Nano 2015, 9, 8997–9011.

    Article  Google Scholar 

  32. Chen, Z. H.; Lin, Y. M.; Rooks, M. J.; Avouris, P. Graphene nano-ribbon electronics. Phys. E 2007, 40, 228–232.

    Article  Google Scholar 

  33. Guo, J. Modeling of graphene nanoribbon devices. Nanoscale 2012, 4, 5538–5548.

    Article  Google Scholar 

  34. Bennett, P. B.; Pedramrazi, Z.; Madani, A.; Chen, Y. C.; de Oteyza, D. G.; Chen, C.; Fischer, F. R.; Crommie, M. F.; Bokor, J. Bottom-up graphene nanoribbon field-effect transistors. Appl. Phys. Lett. 2013, 103, 253114.

    Article  Google Scholar 

  35. Jiao, L. Y.; Wang, X. R.; Diankov, G.; Wang, H. L.; Dai, H. J. Facile synthesis of high-quality graphene nanoribbons. Nat. Nanotechnol. 2010, 5, 321–325.

    Article  Google Scholar 

  36. Koch, M.; Ample, F.; Joachim, C.; Grill, L. Voltagedependent conductance of a single graphene nanoribbon. Nat. Nanotechnol. 2012, 7, 713–717.

    Article  Google Scholar 

  37. Giovannetti, G.; Khomyakov, P. A.; Brocks, G.; Karpan, V. M.; Van den Brink, J.; Kelly, P. J. Doping graphene with metal contacts. Phys. Rev. Lett. 2008, 101, 026803.

    Article  Google Scholar 

  38. Huard, B.; Stander, N.; Sulpizio, J. A.; Goldhaber-Gordon, D. Evidence of the role of contacts on the observed electronhole asymmetry in graphene. Phys. Rev. B 2008, 78, 121402.

    Article  Google Scholar 

  39. Lee, E. J. H.; Balasubramanian, K.; Weitz, R. T.; Burghard, M.; Kern, K. Contact and edge effects in graphene devices. Nat. Nanotechnol. 2008, 3, 486–490.

    Article  Google Scholar 

  40. Blake, P.; Yang, R.; Morozov, S. V.; Schedin, F.; Ponomarenko, L. A.; Zhukov, A. A.; Nair, R. R.; Grigorieva, I. V.; Novoselov, K. S.; Geim, A. K. Influence of metal contacts and charge inhomogeneity on transport properties of graphene near the neutrality point. Solid State Commun. 2009, 149, 1068–1071.

    Article  Google Scholar 

  41. Varykhalov, A.; Scholz, M. R.; Kim, T. K.; Rader, O. Effect of noble-metal contacts on doping and band gap of graphene. Phys. Rev. B 2010, 82, 121101.

    Article  Google Scholar 

  42. Barraza-Lopez, S.; Vanevic, M.; Kindermann, M.; Chou, M. Y. Effects of metallic contacts on electron transport through graphene. Phys. Rev. Lett. 2010, 104, 076807.

    Article  Google Scholar 

  43. Xia, F. N.; Perebeinos, V.; Lin, Y. M.; Wu, Y. Q.; Avouris, P. The origins and limits of metal-graphene junction resistance. Nat. Nanotechnol. 2011, 6, 179–184.

    Article  Google Scholar 

  44. Archambault, C.; Rochefort, A. States modulation in graphene nanoribbons through metal contacts. ACS Nano 2013, 7, 5414–5420.

    Article  Google Scholar 

  45. Mencarelli, D.; Pierantoni, L. Analysis of the metal work function dependence of charge transfer in contacted graphene nanoribbons. Nanomater. Nanotechnol. 2012, 2, DOI: 10.5772/54995.

  46. Walter, A. L.; Nie, S.; Bostwick, A.; Kim, K. S.; Moreschini, L.; Chang, Y. J.; Innocenti, D.; Horn, K.; McCarty, K. F.; Rotenberg, E. Electronic structure of graphene on singlecrystal copper substrates. Phys. Rev. B 2011, 84, 195443.

    Article  Google Scholar 

  47. Vita, H.; Böttcher, S.; Horn, K.; Voloshina, E. N.; Ovcharenko, R. E.; Kampen, T.; Thissen, A.; Dedkov, Y. S. Understanding the origin of band gap formation in graphene on metals: Graphene on Cu/Ir(111). Sci. Rep. 2014, 4, 5704.

    Article  Google Scholar 

  48. Ma, T.; Surnev, S.; Netzer, F. P. Growth of ceria nanoislands on a stepped Au(788) surface. Materials 2015, 8, 5205–5215.

    Article  Google Scholar 

  49. Horcas, I.; Fernández, R.; Gómez-Rodriguez, J. M.; Colchero, J.; Gómez-Herrero, J.; Baro, A. M. WSXM: A software for scanning probe microscopy and a tool for nanotechnology. Rev. Sci. Instrum. 2007, 78, 013705.

    Article  Google Scholar 

  50. Adams, D. L. FitXPS, v 2; University of Aarhus: Denmark, 2004.

    Google Scholar 

  51. Grillo, F.; Früchtl, H.; Francis, S. M.; Richardson, N. V. Site selectivity in the growth of copper islands on Au (111). New J. Phys. 2011, 13, 013044.

    Article  Google Scholar 

  52. Wakabayashi, K.; Sasaki, K. I.; Nakanishi, T.; Enoki, T. Electronic states of graphene nanoribbons and analytical solutions. Sci. Technol. Adv. Mater. 2010, 11, 054504.

    Article  Google Scholar 

  53. Takeuchi, N.; Chan, C. T.; Ho, K. M. Au(111): A theoretical study of the surface reconstruction and the surface electronic structure. Phys. Rev. B 1991, 43, 13899.

    Article  Google Scholar 

  54. Wofford, J. M.; Starodub, E.; Walter, A. L.; Nie, S.; Bostwick, A.; Bartelt, N. C.; Thürmer, K.; Rotenberg, E.; McCarty, K. F.; Dubon, O. D. Extraordinary epitaxial alignment of graphene islands on Au(111). New J. Phys. 2012, 14, 053008.

    Article  Google Scholar 

  55. Koch, N. Energy levels at interfaces between metals and conjugated organic molecules. J. Phys.: Condens. Mat. 2008, 20, 184008.

    Google Scholar 

  56. Kahn, A.; Koch, N.; Gao, W. Y. Electronic structure and electrical properties of interfaces between metals and p-conjugated molecular films. J. Polym. Sci. B Polym. Phys. 2003, 41, 2529–2548.

    Article  Google Scholar 

  57. Vasseur, G.; Fagot-Revurat, Y.; Sicot, M.; Kierren, B.; Moreau, L.; Malterre, D.; Cardenas, L.; Galeotti, G.; Lipton-Duffin, J.; Rosei, F. et al. Quasi one-dimensional band dispersion and surface metallization in long-range ordered polymeric wires. Nature Commun. 2016, 7, 10235.

    Article  Google Scholar 

  58. Marsden, A. J.; Asensio, M. C.; Avila, J.; Dudin, P.; Barinov, A.; Moras, P.; Sheverdyaeva, P. M.; White, T. M.; Maskery, I.; Constantini, G. et al. Is graphene on copper doped? Phys. Status Solidi RRL 2013, 7, 643–646.

    Article  Google Scholar 

  59. de Oteyza, D. G.; Wakayama, Y.; Liu, X.; Yang, W.; Cook, P. L.; Himpsel, F. J.; Ortega, J. E. Effect of fluorination on the molecule–substrate interactions of pentacene/Cu(100) interfaces. Chem. Phys. Lett. 2010, 490, 54–57.

    Article  Google Scholar 

  60. Baldacchini, C.; Allegretti, F.; Gunnella, R.; Betti, M. G. Molecule–metal interaction of pentacene on copper vicinal surfaces. Surf. Sci. 2007, 601, 2603–2606.

    Article  Google Scholar 

  61. McDonald, O.; Cafolla, A. A.; Li, Z. S.; Hughes, G. Synchrotron photoemission studies of pentacene films on Cu (110). Surf. Sci. 2006, 600, 1909–1916.

    Article  Google Scholar 

  62. Tompkins, H. G.; Pinnel, M. R. Low-temperature diffusion of copper through gold. J. Appl. Phys. 1976, 47, 3804–3812.

    Article  Google Scholar 

  63. Macur, J. E.; Vook, R. W. Interdiffusion phenomena in Au/Cu and Cu/Au bilayers. Thin Solid Films 1980, 66, 311–324.

    Article  Google Scholar 

  64. Ravi, R.; Paul, A. Diffusion mechanism in the gold-copper system. J. Mater. Sci. Mater. Electron. 2012, 23, 2152–2156.

    Article  Google Scholar 

  65. Ridene, M.; Wassmann, T.; Pallecchi, E.; Rodary, G; Girard, J. C.; Ouerghi, A. Epitaxial graphene on step bunching of a 6H-SiC(0001) substrate: Aromatic ring pattern and Van Hove singularities. Appl. Phys. Lett. 2013, 102, 111610.

    Article  Google Scholar 

  66. Kramberger, C.; Rauf, H.; Shiozawa, H.; Knupfer, M.; Büchner, B.; Pichler, T.; Batchelor, D.; Kataura, H. Unraveling van Hove singularities in x-ray absorption response of single-wall carbon nanotubes. Phys. Rev. B 2007, 75, 235437.

    Article  Google Scholar 

  67. Mowbray, D. J.; Ayala, P.; Pichler, T.; Rubio, A. Computing C1s X-ray absorption for single-walled carbon nanotubes with distinct electronic type. Mater. Express 2011, 1, 225–230.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Konstantin A. Simonov or Alexei B. Preobrajenski.

Electronic supplementary material

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Simonov, K.A., Vinogradov, N.A., Vinogradov, A.S. et al. Effect of electron injection in copper-contacted graphene nanoribbons. Nano Res. 9, 2735–2746 (2016). https://doi.org/10.1007/s12274-016-1162-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12274-016-1162-2

Keywords

Navigation