Suitable Surface Oxygen Concentration on Copper Contributes to the

Subscriber access provided by University of Groningen

Surfaces, Interfaces, and Catalysis; Physical Properties of Nanomaterials and Materials

Suitable Surface Oxygen Concentration on Copper Contributes to the Growth of Large Graphene Single Crystal Siyu Wu, Wei Zhao, Xinliang Yang, Yijun Chen, Wenjie Wu, Yenan Song, and Qinghong Yuan J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.9b01688 • Publication Date (Web): 07 Aug 2019 Downloaded from pubs.acs.org on August 8, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters

Suitable Surface Oxygen Concentration on Copper Contributes to the Growth of Large Graphene Single Crystal Siyu Wu,† Wei Zhao,‡ Xinliang Yang,† Yijun Chen,† Wenjie Wu,† Yenan Song,†,* and Qinghong Yuan,‡,* † Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, School of Physics and Electronic Science, East China Normal University, Shanghai 200062, China. ‡State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200062, China. KEYWORDS: Cu catalyst, graphene single crystal, oxygen concentration, chemical vapor deposition, growth rate

ACS Paragon Plus Environment

1

The Journal of Physical Chemistry Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 21

ABSTRACT

In this paper, we found that the growth of graphene on Cu oxide foil is significantly affected by the concentration of oxygen. The grain size of graphene grown on Cu substrate with relative high oxygen concentration is much smaller than that on the substrate with lower oxygen concentration. By controlling the oxidation of the Cu substrate at a proper degree, we can obtain millimeter scale graphene single crystal at a growth temperature of 1050 ℃ . Based on our experimental observations, the dual role of oxygen in the CVD growth of graphene was revealed. i) oxygen on Cu surface can contribute to the decomposition of hydrocarbon feedstock and decrease the graphene growth barrier, resulting in increased growth rate and larger grain size of graphene; ii) excess oxygen in the Cu substrate leads to the etching of graphene edge. Our research provides insights to obtain large-area and single-crystalline graphene by choosing proper Cu-oxide substrate.


2

Page 3 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Graphene has potential applications in optoelectronics, spintronics, catalysts, sensors, supercapacitors, solar cells, and lithium ion batteries etc,1-3 due to its exceptional chemical stability, superior mechanical stability, very high thermal and electronic conductivities.4-5 However, the practical applications of graphene have been limited by the lack of high-quality, continuous 2D films. Chemical vapor deposition (CVD) growth of graphene on transition metal catalyst is the most promising for high quality and large area film production at a reasonably low cost.6-16 Cu catalyst is widely used to grow single layer graphene due to the self-limited growth and the extremely low carbon solubility in the bulk,17-20 but it suffers a great drawback of low catalytic activity and a consequently slow growth rate. Introduction of oxygen on the Cu substrate can greatly increase the growth rate of graphene and decrease the nucleation density as well, which is beneficial to the growth of high-quality and large-area graphene.9-11,

21-33

By introducing oxygen into the CVD chamber right before the

introduction of methane, Ruoff et al.10 found that the graphene nucleation rate was greatly reduced due to the passivation of Cu surface active sites. Meanwhile, the surface oxygen also accelerated graphene domain growth and shifted the growth kinetics from edge-attachment–limited to diffusion-limited. Liu et al.30 synthesized single-crystal graphene domains with a lateral size of 0.3 mm and a growth rate of 60 μm s–1 by placing the copper foil above an oxide substrate. They found that the oxide substrate could provide a continuous supply of oxygen to the surface of the Cu catalyst during the CVD growth, the oxygen significantly lowers the energy barrier to the decomposition of the carbon feedstock and increases the growth rate. Despite that oxygen has advantages of promoting the graphene growth rate, excess oxygen decreases the growth rate of graphene due to the etching effect. Studies have shown that low growth rate and small graphene domain are observed when the oxygen exceeds a certain amount.24, 32 Therefore, to achieve the


3


Page 4 of 21

fast growth of large size graphene domains on Cu oxide surface, controlling the oxygen in a proper ratio is essential. Until now, there is no systematic study about the effect of oxygen concentration on the growth of graphene on copper oxide surface. In this report, we demonstrated that the growth of graphene single crystal on Cu foil is highly dependent on the oxygen concentration of Cu oxide. By growing graphene on four different copper oxide substrates (Cu plane and pocket oxidized in air atmosphere and reaction chamber, respectively, which were donated as CuOx-air plane, CuOx-air pocket, CuOx-chamber plane, CuOx-chamber pocket in Figure 1), we found that graphene domains grown on Cu substrates oxidized in the reaction chamber have larger size than that oxidized in the air. Under the same oxidation condition, the size of graphene domain grown on the Cu foil was smaller than that on the pocket. Moreover, the graphene domain size increased with the growth temperature. High growth temperature lead to large graphene domains. Under a growth temperature of 1050 ℃ , graphene grown in Cu pocket oxidized in the reaction chamber had the largest domain size. Further studies revealed that the size of graphene domain was highly related to oxygen concentration in the copper oxide substrate. With the increase of growth temperature, the oxygen concentration in the Cu oxide substrate decreased while the size of graphene domain increased. In addition, Cu substrates oxidized in the reaction chamber had lower oxygen concentration and larger graphene domain. Such observations could be understood from the multiple roles of oxygen in graphene growth, i) promote the decomposition rate of methane and thus the carbon concentration on the substrate; ii) decrease the growth barrier of graphene and change graphene growth kinetics from diffusion-limited to edge-attachment–limited; iii) etch the edge of graphene.


4

Page 5 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Four different samples were prepared to study the effect of oxygen concentration in Cu oxide on the growth behavior of graphene. Two Cu samples were oxidized on a hot plane in air atmosphere for 10 mins, in which one of them was Cu foil and the other was Cu pocket. (Figure 1(a) and (b)) Previous studies reported that the folded Cu pocket made by Cu foil can grow largearea single-crystalline graphene due to the suppressed graphene nucleation in the interior of the pocket caused by the limited gas exchange (200-400 nm gap at the crimped edges) between the interior of the pocket and the air atmosphere.28 The other two Cu samples were oxidized by directly introducing pure oxygen (8 sccm) into the reaction chamber, and oxidation time was also limited to 10 minutes. For this type of oxidation, both Cu foil and Cu pocket were used, as shown in Figure 1(c) and (d). In general, there were four different Cu oxide samples considered in our experiments, which were named as CuOx-air plane, CuOx-air pocket, CuOx-chamber plane, and CuOx-chamber pocket as shown in Figure 1. Graphene grown on these four CuOx samples at different growth temperatures were shown in the lower panels of Figure 1a-d, the growth time is 1 hour. For graphene grown on CuOx-air plane, the nucleation density of graphene decreased with the increase of growth temperature. Meanwhile, the average size of graphene domain increased with the rise of temperature. For graphene grown on CuOx-air pocket, similar growth behavior can be observed except that nucleation density of graphene is much lower than that on CuOx-air plane. Moreover, the average size of graphene domain grown on CuOx-air pocket is much larger than that on the CuOx-air plane, which is consistent with previous report.28, 34-36 Cu foil oxidized in the chamber (CuOx-chamber plane) had similar graphene nucleation density to that of Cu foil oxidized in air (CuOx-air plane) under low growth temperature (900-950℃). However, under high growth temperature, graphene nucleation on CuOx-chamber plane was much lower than that on CuOx-air plane. Meanwhile, the average size


5


Page 6 of 21

of graphene domain grown on CuOx-chamber plane is much larger. In contrast to CuOx-chamber plane, graphene grown on CuOx-chamber pocket has lower nucleation density and larger domain size. In short, graphene grown on Cu substrate oxidized in the chamber has lower nucleation density and larger domain size than that oxidized in the air. Besides, graphene grown in the pocket has lower nucleation density and larger domain size than that on the foil.

Figure 1. Pre-oxidation modes and the OM images of the as-grown single-crystal graphene domains on (a) CuOx-air plane (b) CuOx-air pocket (c) CuOx-chamber plane and (d) CuOxchamber pocket under different temperatures. The growth time of all samples is 1 hour. The effect of the four CuOx substrates on the growth of graphene single crystal is compared more directly in Figure 2. It is clear that the size of graphene domain increases with the rise of


6

Page 7 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


temperature. The maximum size of graphene domains is obtained at the highest growth temperature (1050 °C). Under the same oxidation conditions, graphene domains grown inside the pocket substrate are always larger than that on the foil, and the difference become large with the increase of temperature. (Figure 2a) Similar phenomena can be also observed in Figure 2b in which graphene domains grown in the pocket had low nucleation density and large grain size. By comparing Figure 2a with 2b, we can also see that the size of graphene domains grown on CuOxchamber substrate is larger than that on CuOx-air substrate.

Figure 2. The average size of the graphene domain on Cu foil and Cu pocket oxidized in (a) air and (b) chamber. To understand the effect of oxidation conditions to the growth of graphene, we measured the concentration of oxygen in each CuOx samples. The pocket substrates which could grow large single-crystalline graphene were selected as samples to check the effect of oxygen. At different temperatures, the relationship between the concentration of oxygen in the CuOx-pocket substrate and the size of graphene domain were plotted in Figure 3. The oxidized substrate inside the pocket was characterized by Energy Dispersive X-ray Spectrometry (EDS) scanning, and the


7


Page 8 of 21

concentration of oxygen in CuOx was calculated by the atomic ratio of Cu/O on the substrate surface quantitative analysis. From Figure 3, we can clearly see that the size of graphene domain increases gradually with the rise of temperature. Interestingly, the oxygen concentration in the CuOx substrate decreases gradually with the growth temperature. This means that the grain size of graphene is inversely related to the oxygen concentration in CuOx substrate. Further analysis demonstrates that this kind of relationship is highly linear, which suggests the more decrease in the oxygen concentration, the larger increase in the grain size. Therefore, the black curve (grain size) and the red curve (oxygen concentration in CuOx) in Figure 3a are highly symmetric. Similar phenomenon has been also observed for graphene grown on Cu-pocket oxidized in the chamber. Figure 3b clearly shows that low oxygen concentration in the CuOx substrate leads to large grain size of graphene, and the changes of oxygen concentration are almost linearly related to the graphene grain size. Under the same growth temperature of 1000℃, CuOx obtained in the chamber has lower oxygen concentration (25 at% shown in Figure 3b) than that obtained in the air (32 at% shown in Figure 3a), while the grain size of graphene grown on CuOx-chamber is much larger than that grown on CuOx-air. This clearly demonstrates that low oxygen concentration leads to large graphene size. Previous studies have shown that the role of oxygen in graphene growth is to promote the decomposition of CH4 and decrease the attaching barrier of C to graphene edge,10 which means oxygen in the Cu-oxide substrate is beneficial to the fast growth of graphene domain. However, in this work we found that high oxygen concentration in CuOx substrates played no positive effect to the fast growth of large size graphene domain. For example, CuOx-pocket substrates prepared in air atmosphere always have high oxygen concentration than those prepared in the chamber, while graphene domains grown on CuOx-chamber have larger grain size than those grown on CuOx-air.


8

Page 9 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


This demonstrates that oxygen doesn’t always promote the growth rate of graphene, and excess oxygen leads to the slow growth of graphene instead.

Figure 3. The relationship between the average size of graphene single crystals (red line) grown inside the CuOx-pocket and the oxygen concentration in CuOx-pocket (blue line). (a) Cu pocket oxidized in air (b) Cu pocket oxidized in chamber. From Figure 3a, we can see that under low temperature the percentage of oxygen in CuOx-air is higher than 33 at%. This means the CuOx-air substrate is composed of CuO in which the oxygen concentration is 50 at% and Cu2O in which the oxygen concentration is 33 at%. In comparison, the percentage of oxygen in CuOx-chamber is less than 30 at%, demonstrating the oxidized surface is mainly composed of Cu2O. Because of the low decomposition temperatures, CuO is likely to decompose into Cu2O and O2 at such high temperature.37-38 An equilibrium between CuO and Cu2O may exist: CuO → Cu2O + O2. However, Cu2O is relatively more stable and could survive at high temperatures, which has been detected by a series of experiments.39-42 When the carbon feedstock (e.g. CH4) is introduced in the oxidized Cu substrate, the CH4 molecules are trapped into the surface vacancies of CuOx and dissociate into active species CHx (x=1-3) through C-H bond cleavage and O-H bond formation. Due to the existence of oxygen, the decomposition of CH4


9


Page 10 of 21

become more energetically favorable28 and the C atom attachment barrier also decreases,10 thus the graphene growth is greatly improved. However, at very high oxygen concentration, the surface oxygen can also etch the graphene domain and leads to a slow growth rate of graphene. Therefore, we can conclude that the growth mechanism of graphene on CuOx substrates can be demonstrated in Figure 4. When the oxygen content is extremely low, (Figure 4a) the decomposition of CH4 and the attaching of C atoms to graphene edge is very slow and thus small graphene domains are expected to grow on the substrate. At the same time, the self-cleaning ability of oxygen on copper substrate is weak, and the nucleation density of graphene is high. However, when the oxygen concentration is too high, (Figure 4c) oxygen plays a leading role in the etching of graphene, which makes the obtained graphene single crystal is smaller. By controlling the oxygen concentration at a proper level, the oxygen can play a positive role in promoting the graphene growth rate and reducing the nucleation density.

(a)

(b)

(c)

Figure 4. Illustration of the graphene growth mechanism on Cu oxide surface. (a) Low oxygen concentration (b) Suitable oxygen concentration (c) High oxygen concentration. Figure 5a-d shows the SEM images of single-crystal graphene grown at 900, 950 °C, 1000 °C and 1050 °C. In order to improve the quality of graphene, all the surfaces of Cu foils were smoothened by high temperature annealing since previous studies have shown that roughness of substrate surface has an important effect on the quality and grain size of graphene.43-45 It is worth noting that graphene domain grown at low growth temperature and CuOx with high oxygen


10

Page 11 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


concentration shows equivalent irregular shapes. On CuOx substrate with low oxygen concentration and high growth temperature, the graphene domain has regular hexagonal shape and identifiable angle of 120° (Figure 5d). It is well-known that the graphene morphological evolution is related to the growth condition.31, 33 As a consequence of oxygen incorporation, C attachment at the graphene edge was no longer the rate-limiting step, the growth kinetic altered from edgeattachment-limited growth to diffusion-limited growth. The graphene domain shape changed from a compact hexagon to multi-branched or dendritic shape. Figure 5e shows the hexagonal single crystal graphene films transferred onto the SiO2/Si substrate for Raman test. There are three typical peaks in the spectrum called D peak, G peak, and 2D peak at the wavenumbers of 1350, 1580, and 2680, respectively. The intensity of the D peak gradually decreases as the temperature increases, it means that the defect of the single crystal is reduced and the quality of graphene domain is improved. Also, the intensity ratio of D peak and G peak decreases as the temperature increases. While, the intensity ratios of 2D peak and G peak were between 1.2 and 1.5 for all temperatures, demonstrating the growth of monolayer graphene (>99%) on the Cu substrate.


11


Page 12 of 21

Figure 5. The SEM images of single-crystal graphene grown at (a) 900 °C, (b) 950 °C, (c) 1000 °C, and (d) 1050 °C. (e) The single crystal graphene grown for 1 h on a CuOx-chamber copper pocket, and then transferred onto SiO2/Si substrate. In conclusion, we found that oxygen on the Cu substrate plays a dual role in the CVD growth of graphene single crystal. On one hand, oxygen chemically adsorbed on Cu surface could contribute to the decomposition of hydrocarbon feedstock and decreased the graphene growth barrier. As a result, it accelerated the growth rate, decreased the nucleation density of graphene and finally increased the size of the single crystal. On the other hand, excess surface concentrations of oxygen on Cu would etch the graphene result in small size of graphene single crystal. In this work, by controlling the oxidation of the Cu substrate, we could obtain millimeter scale graphene single crystal at a growth temperature of 1050℃. Our in-depth studies for the role of oxygen in graphene growth would provide useful instruction to control the synthesis of large-area and singlecrystalline graphene on Cu oxide substrate.


12

Page 13 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Copper pre-oxidation. The copper foil was subjected to pre-oxidation treatment of two schemes: one was pre-oxidation on a hot plate in an air atmosphere, the other was directly introducing pure oxygen gas (8 sccm) to the reaction chamber before introducing the carbon source. Oxidation time was 10 minutes. Graphene growth. Graphene was synthesized by copper-catalyzed low-pressure CVD. Firstly, Cu substrates (Alfa Aesar, purity of 99.8%, and thickness of 25 μm) with peroxidation treatment were loaded into a CVD furnace. Then, the CVD system was evacuated to 0.1 Pa. The system was heated to growth temperature followed by thermal annealing for 100 min. Next, the mixture of diluted methane and hydrogen (1:100) was introduced into the CVD system for the graphene growth at different experiment temperatures. Finally, the system was cooled down to the room temperature while maintaining the gas flow. Graphene transfer. The method to fabricate the graphene films onto 300 nm SiO2 substrates was performed by the wet-etching of the copper substrates. The graphene was grown on both sides of the copper foils. The 8 wt% PMMA (polymethyl methacrylate) in an anisole solution was spincoated onto the one side of graphene/copper surface and baked at 90℃ for 2 min. The other side of the sample was exposed to O2 plasma for 60s to remove the unnecessary graphene. After that, the 1M FeCl3 was used to etch the Cu foils, resulting a PMMA/graphene film floating on the surface of the solution. HCl and deionized water were used to wash the PMMA/graphene film for several times, and then transferred to SiO2/Si substrates. After air drying, the PMMA film was removed by acetone, and then the substrate with graphene was rinsed with isopropyl alcohol and finally blow dried with N2 gas.


13


Page 14 of 21

Graphene characterization. The morphology of graphene on copper surface was analyzed by optical microscope (OM) and the field emission scanning electron microscope (FE-SEM, Hitachi S-4800). The Raman spectrum of graphene grown on the surface of copper foil was tested by HR Evolution Raman spectrometer. The laser wavelength was 532 nm, and the quality of graphene was initially measured. The Cu/O ratio of pre-oxidized copper foil was measured by Energy Dispersive X-ray Spectrometry (EDS) as the basis for quantitative analysis.

Corresponding Author *E-mail: [email protected] and [email protected]

Author Contributions The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. Y.S. and Q.Y. designed the experimental part of the project. S.W. and X.Y. realized the fabrication of CVD graphene films. S.W., W.Z., Y.C., and W.W. did the characterizations of as fabricated films. S.W., Y.S., and Q.Y. helped analyze the results and cowrote the manuscript. All the authors participated in the data analysis. Funding Sources This work was financially supported by the National Natural Science Foundation of China (Grant No. 21673075), 111 Project (B12024) and Research and Innovation Fund of East China Normal University. Part of this work was also financially supported by the Open Project of Guangdong Province Key Laboratory of Display Materials and Technology, China (2017B030314031).


14

Page 15 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Notes The authors declare no competing financial interest. Acknowledgements Authors thank Dean Foundation at Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, China and Young Faculty Foundation at School of Physics and Materials Science, East China Normal University, China. Supporting Information The raw data for the plots of oxygen concentration of CuOx in air and in chamber were shown in Table S1 and S2, respectively. The corresponding EDS spectrums and the experimental details were presented in Figure S1 and S2. REFERENCES (1) Zhang, Y.; Tang, T.-T.; Girit, C.; Hao, Z.; Martin, M. C.; Zettl, A.; Crommie, M. F.; Shen, Y. R.; Wang, F. Direct Observation of a Widely Tunable Bandgap in Bilayer Graphene. Nature 2009, 459, 820-823. (2) Kim, K.; Choi, J.-Y.; Kim, T.; Cho, S.-H.; Chung, H.-J. A Role for Graphene in Silicon-based Semiconductor Devices. Nature 2011, 479, 338-344. (3) Novoselov, K. S.; Fal, V.; Colombo, L.; Gellert, P.; Schwab, M.; Kim, K. A Roadmap for Graphene. Nature 2012, 490, 192-200. (4) Novoselov, K. S.; Geim, A. K.; Morozov, S.; Jiang, D.; Katsnelson, M.; Grigorieva, I.; Dubonos, S.; Firsov; AA. Two-dimensional Gas of Massless Dirac Fermions in Graphene. Nature 2005, 438, 197-200.


15


Page 16 of 21

(5) Castro Neto, A. H.; Guinea, F.; Peres, N. M. R.; Novoselov, K. S.; Geim, A. K. The Electronic Properties of Graphene. Rev. Mod. Phys. 2009, 81, 109-162. (6) Wang, H.; Wang, G.; Bao, P.; Yang, S.; Zhu, W.; Xie, X.; Zhang, W.-J. Controllable Synthesis of Submillimeter Single-Crystal Monolayer Graphene Domains on Copper Foils by Suppressing Nucleation. J. Am. Chem. Soc. 2012, 134, 3627-3630. (7) Bae, S.; Kim, H.; Lee, Y.; Xu, X.; Park, J.-S.; Zheng, Y.; Balakrishnan, J.; Lei, T.; Kim, H. R.; Song, Y. I. Roll-to-roll Production of 30-inch Graphene Films for Transparent Electrodes. Nat. Nanotechnol. 2010, 5, 574-588. (8) Yan, Z.; Lin, J.; Peng, Z.; Sun, Z.; Zhu, Y.; Li, L.; Xiang, C.; Samuel, E. L.; Kittrell, C.; Tour, J. M. Toward the Synthesis of Wafer-scale Single-crystal Graphene on Copper Foils. ACS Nano 2012, 6, 9110-9117. (9) Gan, L.; Luo, Z. Turning off Hydrogen to Realize Seeded Growth of Subcentimeter SingleCrystal Graphene Grains on Copper. Acs Nano 2013, 7, 9480-9488. (10) Hao, Y.; Bharathi, M.; Wang, L.; Liu, Y.; Chen, H.; Nie, S.; Wang, X.; Chou, H.; Tan, C.; Fallahazad, B. The Role of Surface Oxygen in the Growth of Large Single-crystal Graphene on Copper. Science 2013, 342, 720-723. (11) Zhou, H.; Yu, W. J.; Liu, L.; Cheng, R.; Chen, Y.; Huang, X.; Liu, Y.; Wang, Y.; Huang, Y.; Duan, X. Chemical Vapour Deposition Growth of Large Single Crystals of Monolayer and Bilayer Graphene. Nat. Commun. 2013, 4, 2096-3103. (12) Mohsin, A.; Liu, L.; Liu, P.; Deng, W.; Ivanov, I. N.; Li, G.; Dyck, O. E.; Duscher, G.; Dunlap, J. R.; Xiao, K. Synthesis of Millimeter-size Hexagon-shaped Graphene Single Crystals on Resolidified Copper. ACS Nano 2013, 7, 8924-8931.


16

Page 17 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(13) Wu, T.; Ding, G.; Shen, H.; Wang, H.; Sun, L.; Jiang, D.; Xie, X.; Jiang, M. Triggering the Continuous Growth of Graphene Toward Millimeter ‐ Sized Grains. Adv. Funct. Mater. 2013, 23, 198-203. (14) Song, Y.; Pan, D.; Cheng, Y.; Wang, P.; Zhao, P.; Wang, H. Growth of Large Graphene Single Crystal Inside a Restricted Chamber by Chemical Vapor Deposition. Carbon 2015, 95, 10271032. (15) Miseikis, V.; Convertino, D.; Mishra, N.; Gemmi, M.; Mashoff, T.; Heun, S.; Haghighian, N.; Bisio, F.; Canepa, M.; Piazza, V. Rapid CVD Growth of Millimetre-sized Single Crystal Graphene Using a Cold-wall Reactor. 2D Mater. 2015, 2, 014006. (16) Nguyen, V. L.; Shin, B. G.; Duong, D. L.; Kim, S. T.; Perello, D.; Lim, Y. J.; Yuan, Q. H.; Ding, F.; Jeong, H. Y.; Shin, H. S. Seamless Stitching of Graphene Domains on Polished Copper (111) Foil. Adv. Mater. 2015, 27, 1376-1382. (17) Lee, S.; Oh, J.; Ruoff, R. S.; Park, S. Residual Acetone Produces Explosives During the Production of Graphite Oxide. Carbon 2012, 50, 1442-1444. (18) Tian, J.; Hu, B.; Wei, Z.; Jin, Y.; Luo, Z.; Xia, M.; Pan, Q.; Liu, Y. Surface Structure Deduced Differences of Copper Foil and Film for Graphene CVD Growth. Appl.Surf.Sci. 2014, 300, 73-79. (19) Wang, H.; Xu, X.; Li, J.; Lin, L.; Sun, L.; Sun, X.; Zhao, S.; Tan, C.; Chen, C.; Dang, W. Surface Monocrystallization of Copper Foil for Fast Growth of Large Single ‐ Crystal Graphene under Free Molecular Flow. Adv. Mater. 2016, 28, 8968-8974. (20) Xu, X.; Zhang, Z.; Qiu, L.; Zhuang, J.; Zhang, L.; Wang, H.; Liao, C.; Song, H.; Qiao, R.; Gao, P. Ultrafast growth of single-crystal graphene assisted by a continuous oxygen supply. Nat. Nanotechnol. 2017, 11, 930-935.


17


Page 18 of 21

(21) Reckinger, N.; Felten, A.; Santos, C. N.; Hackens, B.; Colomer, J.-F. The Influence of Residual Oxidizing Impurities on the Synthesis of Graphene by Atmospheric Pressure Chemical Vapor Deposition. Carbon 2013, 63, 84-91. (22) Magnuson, C. W.; Kong, X.; Ji, H.; Tan, C.; Li, H.; Piner, R.; Ventrice, C. A.; Ruoff, R. S. Copper Oxide as a “Self-cleaning” Substrate for Graphene Growth. J.Mater. Res. 2014, 29, 403-409. (23) Baik, S. I.; Ma, L.; Kim, Y. J.; Li, B.; Liu, M.; Isheim, D.; Yakobson, B. I.; Ajayan, P. M.; Seidman, D. N. An Atomistic Tomographic Study of Oxygen and Hydrogen Atoms and Their Molecules in CVD Grown Graphene. Small 2015, 11, 5968-5974. (24) Li, J.; Wang, D.; Wan, L.-J. Unexpected Functions of Oxygen in a Chemical Vapor Deposition Atmosphere to Regulate Graphene Growth Modes. Chem. Commun. 2015, 51, 15486-15489. (25) Liang, T.; He, G.; Huang, G.; Kong, Y.; Fu, W.; Chen, H.; Wang, Q.; Iwai, H.; Fujita, D.; Liu, Y. Graphene Nucleation Preferentially at Oxygen‐Rich Cu Sites Rather Than on Pure Cu Surface. Adv. Mater. 2015, 27, 6404-6410. (26) Pang, J.; Bachmatiuk, A.; Fu, L.; Yan, C.; Zeng, M.; Wang, J.; Trzebicka, B.; Gemming, T.; Eckert, J.; Rummeli, M. H. Oxidation as a Means to Remove Surface Contaminants on Cu Foil Prior to Graphene Growth by Chemical Vapor Deposition. J. Phys. Chem. C 2015, 119, 13363-13368. (27) Guo, W.; Jing, F.; Xiao, J.; Zhou, C.; Lin, Y.; Wang, S. Oxidative ‐ Etching ‐ Assisted Synthesis of Centimeter‐Sized Single‐Crystalline Graphene. Adv. Mater. 2016, 28, 31523158.


18

Page 19 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(28) Hao, Y.; Wang, L.; Liu, Y.; Chen, H.; Wang, X.; Tan, C.; Nie, S.; Suk, J. W.; Jiang, T.; Liang, T. Oxygen-activated Growth and Bandgap Tunability of Large Single-crystal Bilayer Graphene. Nat. Nanotechnol. 2016, 11, 426-431. (29) Reckinger, N.; Tang, X.; Joucken, F.; Lajaunie, L.; Arenal, R.; Dubois, E.; Hackens, B.; Henrard, L.; Colomer, J.-F. Oxidation-assisted Graphene Heteroepitaxy on Copper Foil. Nanoscale 2016, 8, 18751-18759. (30) Xu, X.; Zhang, Z.; Qiu, L.; Zhuang, J.; Zhang, L.; Wang, H.; Liao, C.; Song, H.; Qiao, R.; Gao, P. Ultrafast Growth of Single-Crystal Graphene Assisted by a Continuous Oxygen Supply. Nat. Nanotechnol. 2016, 11, 930-935. (31) Srinivasan, B. M.; Hao, Y.; Hariharaputran, R.; Rywkin, S.; Hone, J. C.; Colombo, L.; Ruoff, R. S.; Zhang, Y.-W. Oxygen-promoted Chemical Vapor Deposition of Graphene on Copper: A Combined Modeling and Experimental Study. ACS Nano 2018, 12, 9372-9380. (32) Choubak, S.; Levesque, P. L.; Gaufres, E.; Biron, M.; Desjardins, P.; Martel, R. Graphene CVD: Interplay between Growth and Etching on Morphology and Stacking by Hydrogen and Oxidizing Impurities. J. Phys. Chem. C 2014, 118, 21532-21540. (33) Liang, T.; Luan, C.; Chen, H.; Xu, M. Exploring Oxygen in Graphene Chemical Vapor Deposition Synthesis. Nanoscale 2017, 9, 3719-3735. (34) Chen, S.; Ji, H.; Chou, H.; Li, Q.; Li, H.; Suk, J. W.; Piner, R.; Liao, L.; Cai, W.; Ruoff, R. S. Millimeter-Size Single-Crystal Graphene by Suppressing Evaporative Loss of Cu During Low Pressure Chemical Vapor Deposition. Adv. Mater. 2013, 25, 2062-2065. (35) Wei, W.; Jauregui, L. A.; Zhihua, S.; Zhihong, L.; Jiming, B.; Chen, Y. P.; Qingkai, Y. Growth of Single Crystal Graphene Arrays by Locally Controlling Nucleation on Polycrystalline Cu Using Chemical Vapor Deposition. Adv. Mater. 2011, 23, 4897-4897.


19


Page 20 of 21

(36) Li, X.; Magnuson, C. W.; Venugopal, A.; Tromp, R. M.; Hannon, J. B.; Vogel, E. M.; Colombo, L.; Ruoff, R. S. Large-Area Graphene Single Crystals Grown by Low-Pressure Chemical Vapor Deposition of Methane on Copper. J. Am. Chem. Soc. 2011, 133, 2816-2819. (37) Neumann, J.; Zhong, T.; Chang, Y. The Cu− O (copper-oxygen) System. J. Phase. Equilib. 1984, 5, 136-140. (38) Goswami, A.; Trehan, Y. The Thermal Decomposition of Cupric Oxide in Vacuo. Proc. Phys. Soc.Section (B) 1957, 70, 1005. (39) Hono, K.; Pickering, H.; Hashizume, T.; Kamiya, I.; Sakurai, T. Oxygen Segregation and Oxidation on a Copper Surface. Surf. Sci. 1989, 213, 90-102. (40) Poulston, S.; Parlett, P.; Stone, P.; Bowker, M. Surface Oxidation and Reduction of CuO and Cu2O Studied Using XPS and XAES. Surf.Interface Anal. 1996, 24, 811-820. (41) Reckinger, N.; Hooijdonk, E. V.; Joucken, F.; Tyurnina, A. V.; Lucas, S.; Colomer, J. F. Anomalous Moiré Pattern of Graphene Investigated by Scanning Tunneling Microscopy: Evidence of Graphene Growth on Oxidized Cu(111). Nano Res. 2014, 7, 154-162. (42) Hirsimäki, M.; Lampimäki, M.; Lahtonen, K.; Chorkendorff, I.; Valden, M. Investigation of the Role of Oxygen Induced Segregation of Cu During Cu2O Formation on Cu {1 0 0}, Ag/Cu {1 0 0} and Cu (Ag) Alloy. Surf. Sci. 2005, 583, 157-165. (43) Beall, G. W.; Duraia, E.-S. M.; Yu, Q.; Liu, Z. Single Crystalline Graphene Synthesized by Thermal Annealing of Humic Acid over Copper Foils. Physica E: Low-dimensional Systems and Nanostructures 2014, 56, 331-336. (44) Cho, J.; Gao, L.; Tian, J.; Cao, H.; Wu, W.; Yu, Q.; Yitamben, E. N.; Fisher, B.; Guest, J. R.; Chen, Y. P. Atomic-Scale Investigation of Graphene Grown on Cu Foil and the Effects of Thermal Annealing. Acs Nano 2011, 5, 3607-3613.


20

Page 21 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(45) Ramos, W. T. S.; Cunha, T. H. R.; Barcelos, I. D.; Miquita, D. R.; Ferrari, G. A.; de Oliveira, S.; Seara, L. M.; Neto, E. G. S.; Ferlauto, A. S.; Lacerda, R. G. The role of hydrogen partial pressure on the annealing of copper substrates for graphene CVD synthesis. Materials Research Express 2016, 3, 045602.


21

Suitable Surface Oxygen Concentration on Copper Contributes to the

Recommend Documents