Recovery of edge states of graphene nanoislands on an iridium substrate by silicon intercalation  

作　　者：Hui Chen Yande Que Lei Tao Yu-Yang Zhang Xiao Lin Wende Xiao Dongfei Wang Shixuan Du Sokrates T. Pantelides Hong-Jun Gao 

机构地区：[1]Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China [2]Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA [3]Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 3723S, USA

出　　处：《Nano Research》2018年第7期3722-3729,共8页纳米研究（英文版）

基　　金：This work is supported by the National Key Research and Development Projects of China （No. 2016YFA0202300）, the National Basic Research Program of China （Nos. 2013CBA01600 and 2015CB921103）, the National Natural Science Foundation of China （Nos. 61390501, 51325204, 51210003, and 61622116）, and the CAS Pioneer Hundred Talents Program. Work at Yanderbilt 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 Research 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 （XSEDE）, which is supported by the National Science Foundation Grant ACI-1053575.

摘　　要：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.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.

关 键 词：graphene nanoisland zigzag edge edge state scanning tunneling microscopy density functional theory 

分 类 号：O614.825[理学—无机化学] TU362[理学—化学]