由於石墨烯材料具備多種獨特的性質，例如高電子遷移率、高導熱係數、低電阻率…等特性，自2004年被A.K. Geim等人發現以來，便吸引眾多學者們的注意，並將其應用於電晶體、感測元件、場發射元件…等廣泛的研究上。本研究主要分為三大部分：首先利用電化學剝離法製備氧化石墨烯材料、其次透過網版印刷法將氧化石墨烯製成矩形島狀週期陣列，最後探討不同直徑大小的網印氧化石墨烯圖形之場發射特性。
本研究以高定向熱解石墨為原始材料，利用電化學剝離方式製備氧化石墨烯，並以拉曼光譜儀、X光繞射儀和X光電子能譜儀進行材料分析與檢驗，在確認氧化石墨烯之品質與純度後，才進行下一步的網印製程。透過繪圖軟體設計不同直徑大小圖形的遮罩，進行氧化石墨烯的網版印刷，配合光學顯微鏡與掃描式電子顯微鏡的檢視及觀測，發現網印後的氧化石墨烯呈島狀型態，並營造出利於場發射的垂直邊緣，具有極佳的深寬比 (Aspect ratio)，整體形成矩形陣列的場發射源。在進行量測不同直徑大小的氧化石墨烯之場發射特性時，發現氧化石墨烯圖形在直徑150μm條件下有最佳的場發射特性，其起始電場 (Turn-on field)為1.65 V⁄μm，最大場發射電流為20.8μA，場增強因子β為15060，唯直徑100μm之氧化石墨烯圖形受到屏蔽效應 (Screening effect)的作用，未能有較好的場發射特性。
本研究將擁有最佳場發射特性的樣品，於上板陽極旋塗上一層螢光粉，進行元件的光性量測，並且在最大場發射電流值20.8μA時產生最大亮度之綠光，經光譜儀測量後，其發光尖峰波長 (Peak wavelength)位於562nm，而光通量為5.04流明。

Graphene has attracted the attention of most scholars for its unique properties, such as high electron mobility, high thermal conductivity, low resistivity and other physical characteristics which was discovered by A.K Geim since 2004. Graphene can be widely applied such as transistor, sensor, field emission device and other research.
This thesis is divided into three parts: First of all, the graphene oxide is made by electrochemical exfoliation. Secondly, to make graphene oxide as square lattice island array is using screen printing method. Lastly, the field emission of graphene oxide patterns is measured in different diameter.
Graphene oxide is made from highly oriented pyrolytic graphite by electrochemical exfoliation. Before the screen printing process, graphene oxide is analyzed with Raman spectroscopy, XRD, and XPS, which makes sure the quality and purity. In the research, use the AutoCAD software to design the mask in different diameter for the screen printing. In OM and SEM images, the screen printed graphene oxide with the island patterns constructing perpendicular edge shows the best aspect ratio, and then all of them has become square lattice array emitter. When the screen-printed graphene oxide in different diameter is measured, it’s found that the best performance is the diameter of 150μm. The emission behavior of the diameter in 150μm is 1.65 V⁄μm with the maximum emission current of 20.8μA and the field enhancement factor of 15060. It's worth noting that the diameter in 100μm shows the worst emission behavior because of the screening effect.
The luminance measurement of the best condition coating the phosphor shows the maximum amount of green light with the wavelength at 562 nm and the lumens of 5.04 when the emission current is up to 20.8μA.

論文審定書 i
致謝 ii
摘要 iii
Abstract iv
目錄 v
圖目錄 vii
表目錄 x
第 1 章 緒論 1
1.1 文獻回顧 1
1.1.1 石墨烯簡介 1
1.1.2 石墨烯製備方法 3
1.1.3 石墨烯應用於電子場發射源 12
1.2 研究動機 22
1.3 研究方法與論文架構 23
第 2 章 原理 24
2.1 石墨烯物理特性 24
2.1.1 石墨烯基礎理論 24
2.1.2 石墨烯電子傳輸特性 26
2.1.3 石墨烯光學特性 27
2.1.4 石墨烯堆疊結構 28
2.2 場發射理論 30
2.2.1 電子發射形式 30
2.2.2 Fowler-Nordheim theory 30
2.2.3 影響場發射主要因素 32
2.3 儀器原理 33
2.3.1 製程儀器 33
2.3.2 量測儀器 37
第 3 章 實驗流程 45
3.1 材料設計與製備 46
3.1.1 不銹鋼遮罩設計 46
3.1.2 電化學製備石墨烯氧化物 48
3.2 場發射元件製作 49
3.2.1 基板清洗 49
3.2.2 上板製作(陽極) 50
3.2.3 下板製作(陰極) 50
3.3 場發射元件量測 51
3.3.1 電性量測 51
3.3.2 光性量測 51
第 4 章 實驗結果 52
4.1 材料分析 52
4.1.1 拉曼光譜儀分析 (Raman spectrum) 52
4.1.2 X光繞射儀分析 (XRD) 53
4.1.3 X光電子能譜儀分析 (XPS) 54
4.1.4 光學顯微鏡分析 (OM) 55
4.1.5 掃描式電子顯微鏡分析 (SEM) 56
4.2 場發射實驗 58
4.3 場發射發光照度與光譜量測 66
第 5 章 結論 68
參考文獻 69
Published 76

[1] H. P. Boehm, A. Clauss, G. O. Fischer and U. Hofmann, "Das Adsorptionsverhalten sehr dünner Kohlenstoff-Folien," Zeitschrift für anorganische und allgemeine Chemie, vol. 316, pp. 119-127, Jul. 1962.
[2] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, A. A. Firsov, "Electric field effect in atomically thin carbon films," Science, vol. 306, pp. 666 - 669, Jul. 2004.
[3] A. K. Geim , K. S. Novoselov, "The rise of graphene," Nature Materials, vol. 6, pp. 183-191, 2007.
[4] Alexander A. Balandin, Suchismita Ghosh, Wenzhong Bao, Irene Calizo, Desalegne Teweldebrhan, Feng Miao and Chun Ning Lau, "Superior thermal conductivity of single-layer graphene," Nano Lett, vol. 8, pp. 902-907, Feb 2008.
[5] K. I. Bolotin, K. J. Sikes, Z. Jianga, M. Klima, G. Fudenberg, J. Hone, P. Kim, and H. L. Stormer, "Ultrahigh electron mobility in suspended graphene," Solid State Communications, vol. 146, p. 351–355, Jun. 2008.
[6] J. Moser, A. Barreiro and A. Bachtold, "Current-induced cleaning of graphene," Appl. Phys. Lett, vol. 91, p. 163513, Sep. 2007.
[7] R. R. Nair, P. Blake, A. N. Grigorenko, K. S. Novoselov, T. J. Booth, T. Stauber, N. M. R. Peres, A. K. Geim, "Fine Structure Constant Defines Visual Transparency of Graphene," Science, vol. 320, p. 1308, Apr. 2008.
[8] T. Nishimura, K. Kita and A. Toriumi K. Nagashio, "Contact resistivity and current flow path at metal/graphene contact," Appl. Phys. Lett, vol. 97, p. 143514, Oct. 2010.
[9] Wonbong Choi, Indranil Lahiri, Raghunandan Seelaboyina, Yong Soo Kang, "Synthesis of Graphene and Its Applications: A Review," Critical Reviews in Solid State and Materials Sciences, vol. 35, pp. 52-71, Feb. 2010.
[10] Virendra Singh, Daeha Joung, Lei Zhai, Soumen Das, Saiful I. Khondaker, Sudipta Seal, "Graphene based materials: Past, present and future," Progress in Materials Science, vol. 56, pp. 1178-1271, Oct. 2011.
[11] Yuanbo Zhang, Joshua P. Small, William V. Pontius, and Philip Kim, "Fabrication and electric-field-dependent transport measurements of," Appl. Phys. Lett., vol. 86, p. 073104, Feb. 2005.
[12] Guoxiu Wang, , Bei Wang, Jinsoo Park, Ying Wang, Bing Sun, Jane Yao, "Highly efficient and large-scale synthesis of graphene by electrolytic exfoliation," Carbon, vol. 47, p. 3242–3246, Nov. 2009.
[13] Ching-Yuan Su, Ang-Yu Lu, Yanping Xu, Fu-Rong Chen, Andrei N. Khlobystov, Lain-Jong Li, "High-Quality Thin Graphene Films from Fast Electrochemical Exfoliation," ACS NANO, vol. 5, pp. 2332-2339, Nov. 2011.
[14] C.T.J. Low, F.C. Walsh, M.H. Chakrabarti, M.A. Hashim, M.A. Hussain, "Electrochemical approaches to the production of graphene flakes and their potential applications," CARBON, vol. 54, p. 1–21, Apr. 2013.
[15] Sasha Stankovich, Dmitriy A. Dikin, Geoffrey H. B. Dommett, Kevin M. Kohlhaas, Eric J. Zimney,Eric A. Stach, Richard D. Piner, SonBinh T. Nguyen, Rodney S. Ruoff, "Graphene-based composite materials," Nature, vol. 442, pp. 282-286, Jul. 2006.
[16] Sungjin Park, Rodney S. Ruoff, "Chemical methods for the production of graphenes," nature nanotechnology, vol. 4, pp. 217 - 224, Mar. 2009.
[17] Prakash R. Somani, Savita P. Somani, Masayoshi Umeno, "Planer nano-graphenes from camphor by CVD," Chemical Physics Letters, vol. 430, pp. 56-59, Jun. 2006.
[18] A.N. Obraztsov, E.A. Obraztsova, A.V. Tyurnina, A.A. Zolotukhin, "Chemical vapor deposition of thin graphite films of nanometer thickness," Carbon, vol. 45, p. 2017–2021, Jun. 2007.
[19] Qingkai Yu, Jie Lian, Sujitra Siriponglert, Hao Li, Yong P. Chen and Shin-Shem Pei, "Graphene segregated on Ni surfaces and transferred to insulators," Appl. Phys. Lett., vol. 93, p. 113103, Sep. 2008.
[20] Keun Soo Kim, Yue Zhao, Houk Jang, Sang Yoon Lee, Jong Min Kim, Kwang S. Kim, Jong-Hyun Ahn, Philip Kim, Jae-Young Choi and Byung Hee Hong, "Large-scale pattern growth of graphene films for stretchable transparent electrodes," Nature, vol. 5, pp. 706-710, Feb. 2009.
[21] Xuesong Li, Weiwei Cai, Jinho An, Seyoung Kim, Junghyo Nah, Dongxing Yang, Richard Piner, Aruna Velamakanni, Inhwa Jung, Emanuel Tutuc, Sanjay K. Banerjee, Luigi Colombo, Rodney S. Ruoff, "Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils," Science, vol. 5, pp. 1312-1314, May 2009.
[22] Sukang Bae, Hyeongkeun Kim, Youngbin Lee, Xiangfan Xu, Jae-Sung Park, Yi Zheng, "Roll-to-roll production of 30-inch graphene films for transparent electrodes," NATURE NANOTECHNOLOGY, vol. 5, pp. 574-578, Jun. 2010.
[23] Y. Qi, S. H. Rhim, G. F. Sun, M. Weinert, and L. Li, "Epitaxial Graphene on SiC(0001): More than Just Honeycombs," Phys. Rev. Lett, vol. 105, p. 085502, Aug. 2010.
[24] B. C. Brodie, "On the atomic weight of graphite," Phil. Trans. R. Soc. Lond., vol. 149, pp. 249-259, Jan. 1859.
[25] William S. HummersJr., Richard E. Offeman, "Preparation of graphitic oxide," J. Am. Chem. Soc., p. 1339, Mar. 1958.
[26] Sivudu KS, Mahajan YR., "Challenges and opportunities for the mass production of high quality graphene: an analysis of worldwide patents.," Nanotech Insights, vol. 3, pp. 6-19, 2013.
[27] Chenggang Tao, Liying Jiao, Oleg V. Yazyev,Yen-Chia Chen, Juanjuan Feng, Xiaowei Zhang,Rodrigo B. Capaz, James M. Tour, Alex Zettl, Steven G. Louie, Hongjie Dai and Michael F. Crommie, "Spatially resolving edge states of chiral graphene nanoribbons," Nature Physics, vol. 7, pp. 616-620, May 2011.
[28] Sigen Wang, Jianjun Wang, Peter Miraldo, Mingyao Zhu, Ronald Outlaw et al., "High field emission reproducibility and stability of carbon nanosheets and nanosheet-based backgated triode emission devices," Appl. Phys. Lett., vol. 89, p. 183103, Oct. 2006.
[29] Zhong-Shuai Wu, Songfeng Pei, Wencai Ren, Daiming Tang, Libo Gao, Bilu Liu, Feng Li, Chang Liu andHui-Ming Cheng, "Field Emission of Single-Layer Graphene Films Prepared by Electrophoretic Deposition," Advanced Materials, vol. 21, pp. 1756-1760, May 2009.
[30] Min Qian, Tao Feng, Hui Ding, Lifeng Lin, Haibo Li, Yiwei Chen and Zhuo Sun, "Electron field emission from screen-printed graphene films," Nanotech., vol. 20, p. 425702, Sep. 2009.
[31] Zhiming Xiao, Juncong She, Shaozhi Deng, Zikang Tang, Zhibing Li, Jianming Lu and Ningsheng Xu, "Field Electron Emission Characteristics and Physical Mechanism of Individual Single-Layer Graphene," ACS Nano, vol. 4, pp. 6332-6336, Oct. 2010.
[32] J L Qi, X Wang, W T Zheng, H W Tian, C Q Hu and Y S Peng, "Ar plasma treatment on few layer graphene sheets for enhancing their field emission properties," Journal of Physics D: Applied Physics, vol. 43, no. 5, p. 055302, Jan. 2010.
[33] Cheng-Kuang Huang, Yongxi Ou, Yaqing Bie, Qing Zhao and Dapeng Yu, "Well-aligned graphene arrays for field emission displays," Appl. Phys. Lett., vol. 98, p. 263104, Jun. 2011.
[34] Zhicheng Yang, Qing Zhao, Yongxi Ou, Wei Wang, Heng Li et al., "Enhanced field emission from large scale uniform monolayer graphene supported by well-aligned ZnO nanowire arrays," Appl. Phys. Lett., vol. 101, p. 173107, Oct. 2012.
[35] Xianlong Wei , Yoshio Bando and Dmitri Golberg, "Electron emission from individual graphene nanoribbons driven by internal electric field," ACS Nano, vol. 6, pp. 705-711, Nov. 2012.
[36] Leifeng Chen,Hong He, Da Lei, QiQiGe Menggen, Liqin Hu, and Deren Yang, "Field emission performance enhancement of Au nanoparticles doped graphene emitters," Applied Physics Letters, vol. 103, p. 233105, Dec. 2013.
[37] Toby Hallam , Matthew T. Cole , William I. Milne , and Georg S. Duesberg, "Field emission characteristics of contact printed graphene fins," small, May 2013.
[38] Jianlong Liu, Baoqing Zeng, Wenzhong Wang, Nannan Li, Jing Guo, Yong Fang, Jiang Deng, Jiangnan Li, and Chenchun Hao, "Graphene electron cannon: high-current edge emission from aligned graphene sheets," Appl. Phys. Lett., vol. 104, p. 023101, Jan. 2014.
[39] Jiangtao Chen, Linfan Cui, Dongfei Sun, Bingjun Yang, Juan Yang, and Xingbin Yan, "Enhanced field emission properties from aligned graphenes fabricated on micro-hole patterned stainless steel," Appl. Phys. Lett., vol. 105, p. 213111, Nov. 2014.
[40] Chi Li, Xiaoxia Yang, Shuyi Ding, Qing Dai, Xiaohui Qiu, Wei Lei, Xiaobing Zhang, and Baoping Wang, "Field Emission Properties of Triode-Type Graphene Mesh Emitter Arrays," IEEE ELECTRON DEVICE LETTERS, vol. 35, no. 7, pp. 786-788, Jul. 2014.
[41] S. Santandrea, F. Giubileo, V. Grossi, S. Santucci, M. Passacantando et al., "Field emission from single and few-layer graphene flakes," Appl. Phys. Lett., vol. 98, p. 163109, Apr. 2011.
[42] I. Sameera, Ravi Bhatia, Jianyong Ouyang, V. Prasad, and R. Menon, “Electron field emission from reduced graphene oxide on polymer film,” Applied Physics letters, 第 冊102, p. 033102, Jan. 2013.
[43] Mohd Zamri Yusop, Golap Kalita, Yazid Yaakob, Chisato Takahashi and Masaki Tanemura, "Field emission properties of chemical vapor deposited individual graphene," Applied Physics Letters, vol. 104, p. 093501, Mar. 2014.
[44] Alexander Malesevic, Raymond Kemps, Annick Vanhulsel, Manish Pal Chowdhury, Alexander Volodin et al., "Field emission from vertically aligned few-layer graphene," J. Appl. Phys., vol. 104, p. 084301, Oct. 2008.
[45] Navneet Soin, Susanta Sinha Roy, Soumyendu Roy, Kiran Shankar Hazra, Devi S. Misra, Teck H. Lim, Crispin J. Hetherington and James A. McLaughlin, "Enhanced and Stable Field Emission from in Situ Nitrogen-Doped Few-Layered Graphene Nanoflakes," J. Phys. Chem. C, vol. 115, pp. 5366-5372, Mar. 2011.
[46] R. H. Fowler and L. Nordheim, "Electron emission in intense electric fields," Proc. R. Soc. Lond. A, vol. 119, pp. 173-181, May 1928.
[47] A. H. Castro Neto, F. Guinea, N. M. R. Peres, K. S. Novoselov and A. K. Geim, "The electronic properties of graphene," REVIEWS OF MODERN PHYSICS, vol. 81, pp. 109-162, Jan. 2009.
[48] L. G. Cançado, A. Reina,J. Kong and M. S. Dresselhaus, "Geometrical approach for the study of G'band in the Raman spectrum of monolayer graphene,bilayer graphene, and bulk graphite," PHYSICAL REVIEW B, vol. 77, p. 245408, Jun. 2008.
[49] J. N. Fuchs and M. O. Goerbig, "Introduction to the physical properties of graphene," Topics Nanophysics, 2008.
[50] N. Peres, "The electronic properties of graphene and its bilayer," Vacuum, vol. 83, pp. 1248-1252, Jun. 2009.
[51] F. Bonaccorso, Z. Sun, T. Hasan and A. C. Ferrari, "Graphene photonics and optoelectronics," Nature Photonics, vol. 4, pp. 611-622, Aug. 2010.
[52] Sylvain Latil and Luc Henrard, "Charge carriers in few-layer graphene films," PRL, vol. 97, p. 036803, Jul. 2006.
[53] Mauricio Terrones, Andrés R. Botello-Méndez, Jessica Campos-Delgado, Florentino López-Urías, Yadira I. Vega-Cantú, Fernando J. Rodríguez-Macías, Ana Laura Elías, Emilio Mu˜noz-Sandoval, Abraham G. Cano-Márquez, Jean-Christophe Charlier, Humberto Terrones, "Graphene and graphite nanoribbons: Morphology,properties, synthesis, defects and applications," Nano Today, vol. 5, pp. 351-372, Aug. 2010.
[54] S. H. Jo, Y. Tu, Z. P. Huang, D. L. Carnahan, D. Z. Wang, and Z. F. Ren, "Effect of length and spacing of vertically aligned carbon nanotubes on field emission properties," Applied Physics Lett., vol. 82, p. 3520, 2003.
[55] 成會明, 奈米碳管, 五南圖書出版股份有限公司, 2004.
[56] 蕭宏, 半導體製程技術導論, 歐亞書局, 2001.
[57] Edbertho Leal-Quir´os, "Plasma processing of municipal solidwaste," Brazilian Journal of Physics, vol. 34, pp. 1587-1593, Dec. 2004.
[58] lan R.Lewis, Howell G.M. Edwards, Handbook of Raman Spectroscopy, Taylor & Francis, 2001.
[59] M. A. Pimenta, G. Dresselhaus, M. S. Dresselhaus, L. G. Canc¸ado, A. Jorio and R. Saito, "Studying disorder in graphite-based systems by Raman spectroscopy," Physical Chemistry Chemical Physics, vol. 9, pp. 1276-1290, Jan. 2007.
[60] A. C. Ferrari, "Raman spectroscopy of graphene and graphite: Disorder, electron–phonon coupling, doping and nonadiabatic effects," Solid State Communications, vol. 143, pp. 45-57, Apr. 2007.
[61] L.M. Malard, M.A. Pimenta, G. Dresselhaus, M.S. Dresselhaus, "Raman spectroscopy in graphene," Physics Reports, vol. 473, pp. 51-87, Apr. 2009.
[62] A. C. Ferrari, J. C. Meyer, V. Scardaci, C. Casiraghi, M. Lazzeri, F. Mauri, S. Piscanec, D. Jiang, K. S. Novoselov, S. Roth and A. K. Geim, "Raman Spectrum of Graphene and Graphene Layers," Phys. Rev. Lett., vol. 97, p. 187401, Oct. 2006.
[63] Michael Dunlap, J. E. Adaskaveg, "Introduction to the scanning electron microscope," Theory, Practice, & Procedures, 1997.
[64] B. Fultz, J. Howe, "Diffraction and the X-Ray powder diffractometer," Transmission Electron Microscopy and Diffractometry of Materials, 2013.
[65] Mark Engelhard, "X-Ray photoelectron spectroscopy, XPS," [Online]. Available: http://www.emsl.pnnl.gov/emslweb/sites/default/files/engelhard_xps.pdf. [Accessed 4 2016].
[66] Goki Eda, H. Emrah Unalan, Nalin Rupesinghe, Gehan A. J. Amaratunga, and Manish Chhowalla, "Field emission from graphene based composite thin films," Applied Physics Letters, vol. 93, p. 233502, Dec. 2008.
[67] Georgios M. Viskadouros, Minas M. Stylianakis, Emmanuel Kymakis, and Emmanuel Stratakis, "Enhanced field emission from reduced graphene oxide polymer composites," Appl. Mater. Interfaces, vol. 6, pp. 388-393, 2014.
[68] Yanzhong Hong, Zhiyong Wang, and Xianbo Jin, "Sulfuric acid intercalated graphite oxide for graphene preparation," Scientific Reports, vol. 3, p. 3439 , 12 2013.
[69] Dongxing Yanga, Aruna Velamakanni, Gu¨ lay Bozoklu, Sungjin Park, Meryl Stoller, Richard D. Piner, Sasha Stankovich, Inhwa Jung, Daniel A. Field, Carl A. Ventrice Jr., Rodney S. Ruoff,, "Chemical analysis of graphene oxide films after heat and chemical treatments by X-ray photoelectron and Micro-Raman spectroscopy," Carbon, vol. 47, pp. 145-152, 2009.
[70] Chengyuan Hu, Rong Zhou, Chuanjie Fan, Xiaodong Zhou, "Influence of reducing reagent combination in graphene oxide reduction," Micro & Nano Letter, vol. 11, pp. 215-220, 2016.
[71] Hui-Lin Guo, Xian-Fei Wang, Qing-Yun Qian, Feng-Bin Wang, and Xing-Hua Xia, "A green approach to the synthesis of graphene nanosheets," Nano, vol. 3, pp. 2653-2659, 2009.
[72] Wufeng Chen, Lifeng Yan, Prakriti R. Bangal, "Preparation of graphene by the rapid and mild thermal reduction of graphene oxide induced by microwaves," Carbon, vol. 48, pp. 1146-1152, 2010.
[73] Jun Yan, Tong Wei, Bo Shao, Fuqiu Ma, Zhuangjun Fan, Milin Zhang, Chao Zheng, Yongchen Shang, Weizhong Qian, Fei Wei , "Electrochemical properties of graphene nanosheet carbon black composites as electrodes for supercapacitors," Carbon, vol. 48, pp. 1731-1737, 2010.
[74] Bin Xu, Shufang Yue, Zhuyin Sui, Xuetong Zhang, Shanshan Hou, Gaoping Caoa and Yusheng Yanga, "What is the choice for supercapacitors: graphene or graphene oxide?," Energy&Environmental Science, vol. 4, p. 2826, 2011.
[75] C.D.Wagner, W.M.Riggs, L.E.Davis, J.F.Moulder, and G.E.Mullenberg, Handbook of X-ray Photoelectron Spectroscopy, Eden Prairie, Minnesota: Perkin-Elmer Corp., 1979.
[76] Hisato Yamaguchi, Katsuhisa Murakami, X Goki Eda, Takeshi Fujita, Pengfei Guan, WeichaoWang, Cheng Gong, Julien Boisse, Steve Miller, Muge Acik, Kyeongjae Cho, Yves J. Chabal, Mingwei Chen, Fujio Wakaya, Mikio Takai, and Manish Chhowalla, "Field emission from atomically thin edges of reduced graphene oxide," ACS Nano, vol. 5, pp. 4945-4952, May 2011.
[77] Xuan Wang, Linjie Zhi, and Klaus Mullen, "Transparent, conductive graphene electrodes for dye-sensitized solar cells," Nano Lett., vol. 8, pp. 323-327, Nov. 2008.