Recovery of edge states of graphene nanoislands on an iridium substrate by silicon intercalation
),
Hong-Jun Gao1(
)
Download citation
598
Views
28
Downloads
10
Crossref
N/A
WoS
10
Scopus
3
CSCD
Finite-sized graphene sheets, such as graphene nanoislands (GNIs), are promising candidates for practical applications in graphene-based nanoelectronics. GNIs with well-defined zigzag edges are predicted to have spin-polarized edge-states similar to those of zigzag-edged graphene nanoribbons, which can achieve graphene spintronics. However, it has been reported that GNIs on metal substrates have no edge states because of interactions with the substrate.We used a combination of scanning tunneling microscopy, spectroscopy, and density functional theory calculations to demonstrate that the edge states of GNIs on an Ir substrate can be recovered by intercalating a layer of Si atoms between the GNIs and the substrate. We also found that the edge states gradually shift to the Fermi level with increasing island size. This work provides a method to investigate spin-polarized edge states in high-quality graphene nanostructures on a metal substrate.
menu
Recovery of edge states of graphene nanoislands on an iridium substrate by silicon intercalation
), Hong-Jun Gao1(
)
Abstract
Finite-sized graphene sheets, such as graphene nanoislands (GNIs), are promising candidates for practical applications in graphene-based nanoelectronics. GNIs with well-defined zigzag edges are predicted to have spin-polarized edge-states similar to those of zigzag-edged graphene nanoribbons, which can achieve graphene spintronics. However, it has been reported that GNIs on metal substrates have no edge states because of interactions with the substrate.We used a combination of scanning tunneling microscopy, spectroscopy, and density functional theory calculations to demonstrate that the edge states of GNIs on an Ir substrate can be recovered by intercalating a layer of Si atoms between the GNIs and the substrate. We also found that the edge states gradually shift to the Fermi level with increasing island size. This work provides a method to investigate spin-polarized edge states in high-quality graphene nanostructures on a metal substrate.
References(38)
Meunier, V.; Souza Filho, A. G.; Barros, E. B.; Dresselhaus, M. S. Physical properties of low-dimensional sp2-based carbon nanostructures. Rev. Mod. Phys. 2016, 88, 025005.
Dienel, T.; Kawai, S.; Söde, H.; Feng, X. L.; Müllen, K.; Ruffieux, P.; Fasel, R.; Gröning, O. Resolving atomic connectivity in graphene nanostructure junctions. Nano Lett. 2015, 15, 5185–5190.
Joung, D.; Nemilentsau, A.; Agarwal, K.; Dai, C. H.; Liu, C.; Su, Q.; Li, J.; Low, T.; Koester, S. J.; Cho, J. H. Self-assembled three-dimensional graphene-based polyhedrons inducing volumetric light confinement. Nano Lett. 2017, 17, 1987–1994.
Wang, W. L.; Meng, S.; Kaxiras, E. Graphene nanoflakes with large spin. Nano Lett. 2008, 8, 241–245.
Son, Y. W.; Cohen, M. L.; Louie, S. G. Half-metallic graphene nanoribbons. Nature 2006, 444, 347–349.
Cui, P.; Zhang, Q.; Zhu, H. B.; Li, X. X.; Wang, W. Y.; Li, Q. X.; Zeng, C. G.; Zhang, Z. Y. Carbon tetragons as definitive spin switches in narrow zigzag graphene nanoribbons. Phys. Rev. Lett. 2016, 116, 026802.
Wimmer, M.; Adagideli, İ.; Berber, S.; Tománek, D.; Richter, K. Spin currents in rough graphene nanoribbons: Universal fluctuations and spin injection. Phys. Rev. Lett. 2008, 100, 177207.
Topsakal, M.; Sevinçli, H.; Ciraci, S. Spin confinement in the superlattices of graphene ribbons. Appl. Phys. Lett. 2008, 92, 173118.
Ruffieux, P.; Wang, S. Y.; Yang, B.; Sánchez-Sánchez, C.; Liu, J.; Dienel, T.; Talirz, L.; Shinde, P.; Pignedoli, C. A.; Passerone, D. et al. On-surface synthesis of graphene nanoribbons with zigzag edge topology. Nature 2016, 531, 489–492.
Tao, C. G.; Jiao, L. Y.; Yazyev, O. V.; Chen, Y. C.; Feng, J. J.; Zhang, X. W.; Capaz, R. B.; Tour, J. M.; Zettl, A.; Louie, S. G. et al. Spatially resolving edge states of chiral graphene nanoribbons. Nat. Phys. 2011, 7, 616–620.
Shen, J. H.; Zhu, Y. H.; Yang, X. L.; Li, C. Z. Graphene quantum dots: Emergent nanolights for bioimaging, sensors, catalysis and photovoltaic devices. Chem. Commun. 2012, 48, 3686–3699.
Liu, R. L.; Wu, D. Q.; Feng, X. L.; Müllen, K. Bottom-up fabrication of photoluminescent graphene quantum dots with uniform morphology. J. Am. Chem. Soc. 2011, 133, 15221–15223.
Wang, W. L.; Yazyev, O. V.; Meng, S.; Kaxiras, E. Topological frustration in graphene nanoflakes: Magnetic order and spin logic devices. Phys. Rev. Lett. 2009, 102, 157201.
Fernández-Rossier, J.; Palacios, J. J. Magnetism in graphene nanoislands. Phys. Rev. Lett. 2007, 99, 177204.
Heiskanen, H. P.; Manninen, M.; Akola, J. Electronic structure of triangular, hexagonal and round graphene flakes near the Fermi level. New J. Phys. 2008, 10, 103015.
Yoon, Y.; Guo, J. Effect of edge roughness in graphene nanoribbon transistors. Appl. Phys. Lett. 2007, 91, 073103.
Feng, X. F.; Wu, J.; Bell, A. T.; Salmeron, M. An atomic-scale view of the nucleation and growth of graphene islands on Pt surfaces. J. Phys. Chem. C 2015, 119, 7124–7129.
Coraux, J.; N'Diaye, A. T.; Engler, M.; Busse, C.; Wall, D.; Buckanie, N.; Meyer zu Heringdorf, F. -J.; van Gastel, R.; Poelsema, B.; Michely, T. Growth of graphene on Ir(111). New J. Phys. 2009, 11, 023006.
Phark, S. H.; Borme, J.; Vanegas, A. L.; Corbetta, M.; Sander, D.; Kirschner, J. Direct observation of electron confinement in epitaxial graphene nanoislands. ACS Nano 2011, 5, 8162–8166.
Li, Y.; Subramaniam, D.; Atodiresei, N.; Lazić, P.; Caciuc, V.; Pauly, C.; Georgi, A.; Busse, C.; Liebmann, M.; Blügel, S. et al. Absence of edge states in covalently bonded zigzag edges of graphene on Ir(111). Adv. Mater. 2013, 25, 1967–1972.
Lu, J.; Yeo, P. S.; Gan, C. K.; Wu, P.; Loh, K. P. Transforming C60 molecules into graphene quantum dots. Nat. Nanotechnol. 2011, 6, 247–252.
Wang, S. Y.; Talirz, L.; Pignedoli, C. A.; Feng, X. L.; Müllen, K.; Fasel, R.; Ruffieux, P. Giant edge state splitting at atomically precise graphene zigzag edges. Nat. Commun. 2016, 7, 11507.
Leicht, P.; Zielke, L.; Bouvron, S.; Moroni, R.; Voloshina, E.; Hammerschmidt, L.; Dedkov, Y. S.; Fonin, M. In situ fabrication of quasi-free-standing epitaxial graphene nanoflakes on gold. ACS Nano 2014, 8, 3735–3742.
Deniz, O.; Sánchez-Sánchez, C.; Dumslaff, T.; Feng, X. L.; Narita, A.; Müllen, K.; Kharche, N.; Meunier, V.; Fasel, R.; Ruffieux, P. Revealing the electronic structure of silicon intercalated armchair graphene nanoribbons by scanning tunneling spectroscopy. Nano Lett. 2017, 17, 2197–2203.
Meng, L.; Wu, R. T.; Zhou, H. T.; Li, G.; Zhang, Y.; Li, L. F.; Wang, Y. L.; Gao, H. J. Silicon intercalation at the interface of graphene and Ir(111). Appl. Phys. Lett. 2012, 100, 083101.
Mao, J. H.; Huang, L.; Pan, Y.; Gao, M.; He, J. F.; Zhou, H. T.; Guo, H. M.; Tian, Y.; Zou, Q.; Zhang, L. Z. et al. Silicon layer intercalation of centimeter-scale, epitaxially grown monolayer graphene on Ru (0001). Appl. Phys. Lett. 2012, 100, 093101.
Meng, L.; Wu, R. T.; Zhang, L. Z.; Li, L. F.; Du, S. X.; Wang, Y. L.; Gao, H. J. Multi-oriented moiré superstructures of graphene on Ir(111): Experimental observations and theoretical models. J. Phys. : Condens. Matter 2012, 24, 314214.
N'Diaye, A. T.; Bleikamp, S.; Feibelman, P. J.; Michely, T. Two- dimensional Ir cluster lattice on a graphene moiré on Ir(111). Phys. Rev. Lett. 2006, 97, 215501.
Coraux, J.; N'Diaye, A. T.; Busse, C.; Michely, T. Structural coherency of graphene on Ir(111). Nano Lett. 2008, 8, 565–570.
Jin, L.; Fu, Q.; Mu, R. T.; Tan, D. L.; Bao, X. H. Pb intercalation underneath a graphene layer on Ru(0001) and its effect on graphene oxidation. Phys. Chem. Chem. Phys. 2011, 13, 16655–16660.
Kim, H. W.; Ku, J.; Ko, W.; Jeon, I.; Kwon, H.; Ryu, S.; Kahng, S. J.; Lee, S. H.; Hwang, S. W.; Suh, H. Strong interaction between graphene edge and metal revealed by scanning tunneling microscopy. Carbon 2014, 78, 190–195.
Li, Y. Y.; Chen, M. X.; Weinert, M.; Li, L. Direct experimental determination of onset of electron-electron interactions in gap opening of zigzag graphene nanoribbons. Nat. Commun. 2014, 5, 4311.
Hämäläinen, S. K.; Sun, Z. X.; Boneschanscher, M. P.; Uppstu, A.; Ijäs, M.; Harju, A.; Vanmaekelbergh, D.; Liljeroth, P. Quantum- confined electronic states in atomically well-defined graphene nanostructures. Phys. Rev. Lett. 2011, 107, 236803.
Kresse, G.; Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. Rev. B 1993, 47, 558–561.
Kresse, G.; Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 1996, 54, 11169–11186.
Kresse, G.; Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999, 59, 1758–1775.
Ceperley, D. M.; Alder, B. J. Ground state of the electron gas by a stochastic method. Phys. Rev. Lett. 1980, 45, 566–569.
Perdew, J. P.; Zunger, A. Self-interaction correction to density-functional approximations for many-electron systems. Phys. Rev. B 1981, 23, 5048–5079.
Publication history
Copyright
Acknowledgements
This work is supported by National Key Research & Development Projects of China (No. 2016YFA0202300), National Basic Research Program of China (Nos. 2013-CBA01600 and 2015CB921103), National Natural Science Foundation of China (Nos. 61390501, 51325204, 51210003, and 61622116), and the CAS Pioneer Hundred Talents Program. Work at Vanderbilt is partially supported by the Department of Energy grant DE- FG02-09ER46554 and by the McMinn Endowment. Y. Y. Z and S. T. P acknowledge the National Energy Re-search Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, and the Extreme Science and Engineering Discovery Environment (XS-EDE), which is supported by National Science Foundation Grant ACI-1053575. A portion of the research was performed in CAS key laboratory of Vacuum Physics.
FEEDBACK 
TOP