本論文主要探討利用垂直冷壁式有機金屬化學氣相沉積法(Cold-wall metal organic chemical vapor deposition; MOCVD)及自組反應式射頻磁控濺鍍系統(Homemade reactive radio-frequency magnetron sputtering; RFMS) 藉由不同成長條件，將奈米微粒、奈米管及奈米箔狀等不同奈米形貌的導電氧化物二氧化銥(Iridium dioxide; IrO2)成長於奈米碳管(Carbon nanotubes; CNT)基底的表面上，形成奈米複合材料，之後探討其晶體結晶相及結構相關訊息。場發射式掃描電子顯微鏡(Field emission scanning electron microscope; FESEM)、場發射式穿透電子顯微鏡(Field emission transition microscope; FETEM)、X光繞射儀(X-ray diffractometer; XRD)、X光能譜分析儀(Energy-dispersive X-ray spectroscopy; EDX)與微拉曼散射儀(Micro-Raman scattering)將用來分析奈米複合材料之表面形貌、晶體大小、晶體方向、晶體組成及晶體結構。X光光子能譜儀(X-ray photoelectron spectroscopy; XPS)則用於分析晶體化學鍵結與組成。此外，奈米複合材料的場發特性與電化學特性也將於此論文探討。
在使用有機金屬化學氣相沉積法做成長時，掃描電子影像顯示在矽基板上，奈米微粒狀的二氧化銥大量且均勻大小的附著在奈米碳管壁上，並藉由能量散佈能譜確認二氧化銥奈米微粒的沉積。穿透電子影像顯示由於晶格匹配因素，二氧化銥傾向於(110)面成長於奈米碳管(001)面上，並且有些微的缺陷出現在表面上。另外，藉由高角度環狀暗場影像可以確認在沉積二氧化銥後，奈米碳管仍然保持著空心管狀的結構。在場發射實驗中奈米複合材料顯示在每平方0.1微安培下其具有較低的啟動電場約為每微米1伏特與在每平方1毫安培下其具有較低的臨界電場約為每微米2.7伏特。其奈米複合材料具有約7.4 x 103的高場發射增強因子與長時間的穩定性。
當沉積時間拉長後，掃瞄電子影像顯示二氧化銥將會從奈米顆粒變成奈米管的形貌，將可提高二氧化銥的表面積比。此類樣品將可應用於超級電容(Supercapacitor)元件中。結果中顯示，密集的二氧化銥奈米管是呈現孔狀結構成長於不鏽鋼基板上的奈米碳管表面。穿透電子影像則顯示金紅石結構的二氧化銥帶著頂部開口的薄壁管狀形貌往[001]優選方向成長於奈米碳管上。因為二氧化銥表面提供的準電容(Pseudocapacitance)特性，在碳管基底上成長二氧化銥將可提高奈米碳管薄膜的電容特性。恆電流放電實驗中，奈米化合物的比電容值從純奈米碳管的每克11法拉增加到了約為每克69法拉比。在交流阻抗分析法中奈米化合物也顯示其比純奈米碳管具有較接近理想電容的特性。
另外，使用反應式射頻磁控濺鍍系統做成長時，奈米微粒狀的二氧化銥附著在奈米碳管壁顯示相似的特性。在場發射實驗中顯示在每平方0.1微安培下其具有較低的啟動電場約為每微米0.7伏特與在每平方1毫安培下其具有較低的臨界電場約為每微米2.3伏特。其奈米化合物同樣具有約1 x 104的高場發射增強因子與長時間的穩定性。結果顯示二氧化銥奈米微粒狀與奈米碳管的奈米化合物在場發射元件中將是個具優勢的候選材料。
當沉積時間拉長時，大表面積的氧化銥奈米箔將可於不鏽鋼基板上的奈米碳管基底表面成長出來。掃描電子影像顯示成長於直徑約40奈米之奈米碳管上的氧化銥奈米箔呈現透明狀，其厚度約為2-3奈米，長寬大約為400-500奈米。從穿透電子影像中可得知，氧化銥奈米箔是由非晶態的二氧化銥、二氧化銥與金屬銥所組成。在微拉曼散射光譜中氧化銥箔的半高寬同樣顯示其奈米結構的特性與複雜的組成。此奈米化合物更可大幅度的提高奈米碳管的電化學特性而應用於超級電容元件中。在循環伏安法中，二氧化銥奈米箔的增加，將奈米碳管的比電容值從每克17.7法拉提升到每克317法拉。此外，恆電流充放電實驗中，奈米化合物的比電容在-1伏特到0伏特間、2000次循環充放電後，仍然保持在約為每克370法拉。結果顯示二氧化銥奈米管、奈米箔與奈米碳管的奈米化合物也可應用於超級電容元件。
本研究顯示，奈米微粒狀的二氧化銥將可做為奈米碳管的保護層而應用於場發射元件中。同時，奈米箔狀的二氧化銥成長於奈米碳管上展現其高的體表面積比，顯示其具有應用於超級電容的潛力。

Iridium oxide (IrOx) with various nanometer scale size morphologies, such as nanoparticles (NP), nanotubes (NT) and nanofoils (NF), were deposited on the surface of multiwall carbon nanotubes (CNT) via vertical-flow cold-wall metal organic chemical vapor deposition (MOCVD) and reactive radio-frequency magnetron sputtering (RFMS) techniques. The detailed characterization focusing on the morphologies, sizes, crystal structures, crystal orientations, and chemical composition of various IrOx/CNT samples have been carried out by means of field-emission scanning electron microscope (FESEM), transition electron microscope (FETEM), X-ray diffractometer (XRD), Energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and micro-Raman scattering. The field emission properties and electrochemical characteristics of IrOx/CNT nanocomposites were also studied.
The SEM image of IrO2 nanostructures, deposited on CNT by MOCVD, showed a dense coalescence of IrO2NP with uniform size distribution on the nanotube walls. EDX confirmed the growth of the IrO2 nanoparticles on CNT. TEM showed IrO2 deposited on CNT with the relationship (110)IrO2/(001)CNT and lattice mismatch related defects appeared at the interfaces. The high angle annular dark field (HAADF) image indicates that the center region of the CNT still retains a tubular structure after depositing IrO2NP. The combined effects of the geometrical structure of IrO2NP/CNT, and the natural conducting and enhanced resistance to oxidation properties of IrO2 lead to a low turn-on field of 1 V/m at a current density of 0.1 A/cm2, a low threshold field of 2.7 V/m at a current density of 1 mA/cm2, a high field enhancement factor of 7.4 x 103, and long-term stability for the IrO2NP/CNT nanocomposites. The results indicated that IrO2NP can be used as a protective layer on CNT, providing stable and uniform field emission applications.
By increasing the growth times, the FESEM micrographs showed that the surface morphology of the as-deposited IrO2 varied from nanoparticle to nanotube. The nanotube-like structure can increase the surface-to-volume ratio which makes the IrO2NT/CNT nanocomposites as attractive candidate for supercapacitor applications. Synthesis of the hierarchical structure with open porosity has been performed by a dense deposition of IrO2 short tubes along the long wires of CNT on a substrate of stainless steel (SUS). The rutile IrO2 tube grows along the [001] direction with an opening at its tip, surrounded by very thin walls. The IrO2 addition on the CNT template increased the capacitance of the CNT thin film effectively, because of pseudocapacitance of the IrO2 surface. For this particular composite, featured with two tubular nanostructures, the specific capacitance increases from 11 F g-1 (CNT) to 69 F g-1 (IrO2NT/CNT), measured using the galvanostatic discharge experiment. Its property of fast retrieving the stored charge was assured in the impedance measurement, showing the IrO2NT/CNT nanocomposites electrode was similar to an ideal capacitor.
Similar characterizations were also performed for nanoparticle like IrO2 coated on CNT by RFMS. The as-synthesized IrO2NP on CNT showed a low turn-on field of 0.7 V/m at a current density of 0.1 A/cm2, a low threshold field of 2.3 V/m at a current density of 1 mA/cm2, a high field enhancement factor of 1 x 104. In addition, long-term stability for the IrO2-coated CNT was also demonstrated.
Large surface area IrOxNF, suitable for supercapacitor applications, were deposited on the CNT/SUS templates by RFMS. This IrOxNF/CNT/SUS electrode was featured with intriguing IrOx curved foils of 2-3 nm in thickness and 400-500 nm in height, grown on top of the vertically aligned CNT film with a tube diameter 40 nm. These nanofoils were moderately oxidized during the process of reactive sputtering and appear translucent under the electron microscope. Detailed structural analysis showed they comprise of contiguous grains of iridium metal, iridium dioxide, and glassy iridium oxide. The attribute of nanosized iridium oxide was further manifested by the considerable Raman line broadening. Two capacitive properties of the electrode are significantly enhanced with addition of the curved IrOx foils. Firstly, the IrOxNF reduced the electrode ohmic resistance, which measures 3.5  cm2 for CNT/SUS and 2.5  cm2 for IrOxNF/CNT/SUS using impedance spectroscopy. Secondly, IrOxNF also raised the electrode capacitance from 17.7 F g-1 for CNT/SUS to 317 F g-1 for IrOxNF/CNT/SUS, measured with cyclic voltammetry. This notable increase was further confirmed with the galvanostatic charge/discharge experiment, measuring 370 F g-1 after uninterrupted 2000 cycles between -1.0 and 0.0 V (vs Ag/AgCl).
We have demonstrated that the IrO2NP coated on CNT can be used as a protective layer on CNT, providing stable and uniform field emission applications. The large surface area IrOxNF deposited on the CNT/SUS templates by RFMS are suitable for supercapacitor applications.

[1] Rogers, D. B., R. D. Shannon, A. W. Sleight, and J. L. Gillson, “Crystal Chemistry of Metal Dioxides with Rutile-Related Structures,” Inorg. Chem., Vol.8, No.4, pp.841-849 (1969).
[2] Mattheiss, L. F., “Electronic Structure of RuO2, OsO2, and IrO2,” Phys. Rev. B, Vol.13, No.6, pp.2433-2450 (1976).
[3] Bolzan, A. A., C. Fong, B. J. Kennedy, and C. J. Howard, “Structural Studies of Rutile-Type Metal Dioxides,” Acta Crystallographica Section B, Vol.53, No.3, pp.373-380 (1997).
[4] Huang, Y. S., S. S. Lin, C. R. Huang, M. C. Lee, T. E. Dann, and F. Z. Chien, “Raman Spectrum of IrO2,” Solid State Commun., Vol.70, No.5, pp.517-522 (1989).
[5] Ryden, W. D., and A. W. Lawson, “Magnetic Susceptibility of IrO2 and RuO2,” J. Chem. Phys., Vol.52, No.12, pp.6058-6061 (1970).
[6] Conway, B. E., and J. Mozota, “Surface and Bulk Processes at Oxidized Iridium Electrodes-II. Conductivity-Switched Behaviour of Thick Oxide Films,” Electrochim. Acta, Vol.28, No.1, pp.9-16 (1983).
[7] Ryden, W. D., A. W. Lawson, and C. C. Sartain, “Electrical Transport Properties of IrO2 and RuO2,” Phys. Rev. B, Vol.1, No.4, pp.1494-1500 (1970).
[8] Chalamala, B. R., Y. Wei, R. H. Reuss, S. Aggarwal, B. E. Gnade, R. Ramesh, J. M. Bernhard, E. D. Sosa, and D. E. Golden, “Effect of Growth Conditions on Surface Morphology and Photoelectric Work Function Characteristics of Iridium Oxide Thin Films,” Appl. Phys. Lett., Vol.74, No.10, pp.1394-1396 (1999).
[9] Chiang, D., P. Z. Lei, F. Zhang, and R. Barrowcliff, “Dynamic EFM Spectroscopy Studies on Electric Force Gradients of IrO2 Nanorod Arrays,” Nanotechnology, Vol.16, No.3, pp.S35-S40 (2005).
[10] Chalamala, B. R., Y. Wei, G. Rossi, B. G. Smith, and R. H. Reuss, “Fabrication of Iridium Field Emitter Arrays,” Appl. Phys. Lett., Vol.77, No.20, pp.3284-3286 (2000).
[11] Chen, R. S., Y. S. Huang, Y. M. Liang, C. S. Hsieh, D. S. Tsai, and K. K. Tiong, “Field Emission from Vertically Aligned Conductive IrO2 Nanorods,” Appl. Phys. Lett., Vol.84, No.9, pp.1552-1554 (2004).
[12] Cogan, S. F., T. D. Plante, R. S. McFadden, and R. D. Rauh, “Solar Modulation in a-WO3/a-IrO2 and c-KxWO3+(x/2)/a-IrO2 Complementary Electrochromic Windows,” Solar Energy Materials, Vol.16, No.5, pp.371-382 (1987).
[13] Nishio, K., Y. Watanabe, and T. Tsuchiya, “Preparation and Properties of Electrochromic Iridium Oxide Thin Film by sol-gel Process,” Thin Solid Films, Vol.350, No.1-2, pp.96-100 (1999).
[14] Osaka, A., T. Takatsuna, and Y. Miura, “Iridium Oxide Films via sol-gel Processing,” J. Non-Cryst. Solids, Vol.178, pp.313-319 (1994).
[15] Ioroi, T., N. Kitazawa, K. Yasuda, Y. Yamamoto, and H. Takenaka, “Iridium Oxide/Platinum Electrocatalysts for Unitized Regenerative Polymer Electrolyte Fuel Cells,” J. Electrochem. Soc., Vol.147, No.6, pp.2018-2022 (2000).
[16] de Oliveira-Sousa, A., M. A. S. da Silva, S. A. S. Machado, L. A. Avaca, and P. de Lima-Neto, “Influence of the Preparation Method on the Morphological and Electrochemical Properties of Ti/IrO2-Coated Electrodes,” Electrochim. Acta, Vol.45, No.27, pp.4467-4473 (2000).
[17] Fog, A., and R. P. Buck, “Electronic Semiconducting Oxides as pH Sensors,” Sens. Actuators, Vol.5, No.2, pp.137-146 (1984).
[18] Yao, S., M. Wang, and M. Madou, “A pH Electrode Based on Melt-Oxidized Iridium Oxide,” J. Electrochem. Soc., Vol.148, No.4, pp.H29-H36 (2001).
[19] Lue, J. C., and S. Chao, “Fabrication and Characterization of IrO2-based Microsensors for Fast Detection of Carbon Dioxide,” Jpn. J. Appl. Phys., Part 1, Vol.36, No.4 A, pp.2292-2297 (1997).
[20] Nakamura, T., Y. Nakao, A. Kamisawa, and H. Takasu, “Preparation of Pb(Zr, Ti)O3 Thin Films on Ir and IrO2 Electrodes,” Jpn. J. Appl. Phys., Part 1, Vol.33, No.9B, pp.5207-5210 (1997).
[21] Nakamura, T., Y. Nakao, A. Kamisawa, and H. Takasu, “Preparation of Pb(Zr,Ti)O3 Thin Films on Electrodes including IrO2,” Appl. Phys. Lett., Vol.65, No.12, pp.1522-1524 (1994).
[22] Jo, W., S. M. Cho, H. M. Lee, D. C. Kim, and J. U. Bu, “Effect of Oxygen to Argon Ratio on Growth of Bi4Ti3O12 Thin Films on Ir and IrO2 Prepared by Radio-Frequency Magnetron Sputtering,” Jpn. J. Appl. Phys., Part 1, Vol.38, No.5A, pp.2827-2830 (1999).
[23] Igarashi, Y., K. Tani, M. Kasai, K. Ashikaga, and T. Ito, “Submicron Ferroelectric Capacitors Fabricated by Chemical Mechanical Polishing Process for High-Density Ferroelectric Memories,” Jpn. J. Appl. Phys., Part 1, Vol.39, No.4B, pp.2083-2086 (2000).
[24] Sakoda, T., T. S. Moise, S. R. Summerfelt, L. Colombo, G. Xing, S. R. Gilbert, A. L. S. Loke, S. Ma, R. Kavari, L. A. Wills, and J. Amano, “Hydrogen-Robust Submicron IrOx/Pb(Zr, Ti)O3/Ir Capacitors for Embedded Ferroelectric Memory,” Jpn. J. Appl. Phys., Part 1, Vol.40, No.4B, pp.2911-2916 (2001).
[25] Jo, W., “Structural and Ferroelectric Properties of Bi4Ti3O12 thin films on IrO2 Prepared by RF Magnetron Sputtering,” Appl. Phys. A, Vol.72, No.1, pp.81-84 (2001).
[26] Song, Y. J., H. H. Kim, S. Y. Lee, D. J. Jung, B. J. Koo, J. K. Lee, Y. S. Park, H. J. Cho, S. O. Park, and K. Kim, “Integration and Electrical Properties of Diffusion Barrier for High Density Ferroelectric Memory,” Appl. Phys. Lett., Vol.76, No.4, pp.451-453 (2000).
[27] Pinnow, C. U., I. Kasko, C. Dehm, B. Jobst, M. Seibt, and U. Geyer, “Preparation and Properties of DC-Sputtered IrO2 and Ir Thin Films for Oxygen Barrier Applications in Advanced Memory Technology,” J. Vac. Sci. Technol. B, Vol.19, No.5, pp.1857-1865 (2001).
[28] Pinnow, C. U., I. Kasko, N. Nagel, S. Poppa, T. Mikolajick, C. Dehm, W. Hosler, F. Bleyl, F. Jahnel, M. Seibt, U. Geyer, and K. Samwer, “Influence of Deposition Conditions on Ir/IrO2 Oxygen Barrier Effectiveness,” J. Appl. Phys., Vol.91, No.12, pp.9591-9597 (2002).
[29] Shin, J. C., C. S. Hwang, and H. J. Kim, “Electrical Conduction Properties of Sputter-Grown (Ba, Sr)TiO3 Thin Films Having IrO2 Electrodes,” Appl. Phys. Lett., Vol.76, No.12, pp.1609-1611 (2000).
[30] Lee, H. S., W. S. Um, K. T. Hwang, H. G. Shin, Y. B. Kim, and K. H. Auh, “Ferroelectric Properties of Pb(Zr, Ti)O3 Thin Films Deposited on Annealed IrO2 and Ir Bottom Electrodes,” J. Vac. Sci. Technol. A, Vol.17, No.5, pp.2939-2943 (1999).
[31] Kushida-Abdelghafar, K., and Y. Fujisaki, “IrO2/Pb(ZrxTi1-x)O3(PZT)/Pt Ferroelectric Thin-Film Capacitors Resistant to an Interlayer-Dielectric-Deposition Process,” Jpn. J. Appl. Phys., Part 2, Vol.37, No.9B, pp.L804-L805 (1994).
[32] Tankiewicz, S., B. Morten, M. Prudenziati, and L. J. Golonka, “New Thick-Film Material for Piezoresistive Sensors,” Sens. Actuators A., Vol.95, No.1, pp.39-45 (2001).
[33] Chalamala, B. R., R. H. Reuss, K. A. Dean, E. Sosa, and D. E. Golden, “Field Emission Characteristics of Iridium Oxide Tips,” J. Appl. Phys., Vol.91, No.9, pp.6141-6146 (2002).
[34] Liu, D. Q., S. H. Yu, S. W. Son, and S. K. Joo, “Electrochemical Performance of Iridium Oxide Thin Film for Supercapacitor Prepared by Radio Frequency Magnetron Sputtering Method,” ECS Trans., Vol.16, No.1, pp.103-109 (2008).
[35] Chen, R. S., A. Korotcov, Y. S. Huang, and D. S. Tsai, “One-Dimensional Conductive IrO2 Nanocrystals,” Nanotechnology, Vol.17, pp.R67-R87 (2006).
[36] Radushkevich, V. and V. M. Lukyanovich, “О Структуре Углерода, Образующегося При Термическом Разложении Окиси Углерода На Железном Контакте,” Soviet J. Phys. Chem., Vol.26, pp. 88-95 (1952).
[37] Oberlin, A., M. Endo, and T. Koyama, “Filamentous Growth of Carbon through Benzene Decomposition,” J. Cryst. Growth, Vol.32, No.3, pp.335-349 (1976).
[38] Abrahamson, J., P. G. Wiles, and B. L. Rhoades, “Structure of Carbon Fibers Found on Carbon arc Anodes,” Carbon, Vol.37, No.11, pp.1873-1874 (1999).
[39] Izvestiya Akademii Nauk SSSR, Metals. (1982), Vol.3, pp.12–17 (in Russian).
[40] Tennent, H. G., “Carbon Fibrils, Method for Producing Same and Compositions Containing Same,” No.US 4663230, (1982)
[41] Iijima, S., “Helical Microtubules of Graphitic Carbon,” Nature, Vol.354, No.6348, pp.56-58 (1991).
[42] Baughman, R. H., A. A. Zakhidov, and W. A. de Heer, “Carbon Nanotubes--the Route Toward Applications,” Science, Vol.297, No.5582, pp.787-792 (2002).
[43] Ajayan, P. M., and O. Z. Zhou, “Applications of Carbon Nanotubes,” Top. Appl. Phys., Vol.80, pp.391-425 (2001).
[44] Daenen, M., R. D. de Fouw, B. Hamers, P. G. A. Janssen, K. Schouteden, and M. A. J. Veld, “A Review of Current Carbon Nanotube Technologies,” Eindhoven University of Technology
[45] Wang, X., Q. Li, J. Xie, Z. Jin, J. Wang, Y. Li, K. Jiang, and S. Fan, “Fabrication of Ultralong and Electrically Uniform Single-Walled Carbon Nanotubes on Clean Substrates,” Nano Lett., Vol.9, No.9, pp.3137-3141 (2009).
[46] Balasubramanian, K., and M. Burghard, “Biosensors Based on Carbon Nanotubes,” Anal. Bioanal. Chem., Vol.385, No.3, pp.452-468 (2006).
[47] Gong, K., Y. Yan, M. Zhang, L. Su, S. Xiong, and L. Mao, “Electrochemistry and Electroanalytical Applications of Carbon Nanotubes: A Review,” Anal. Sci., Vol.21, No.12, pp.1383-1393 (2005).
[48] Dillon, A. C., K. M. Jones, T. A. Bekkedahl, C. H. Kiang, D. S. Bethune, and M. J. Heben, “Storage of Hydrogen in Single-Walled Carbon Nanotubes,” Nature, Vol.386, No.6623, pp.377-379 (1997).
[49] Ren, Z. F., Z. P. Huang, J. W. Xu, J. H. Wang, P. Bush, M. P. Siegal, and P. N. Provencio, “Synthesis of Large Arrays of Well-Aligned Carbon Nanotubes on Glass,” Science, Vol.282, No.5391, pp.1105-1107 (1998).
[50] Lu, X., and Z. Chen, “Curved Pi-Conjugation, Aromaticity, and the Related Chemistry of Small Fullerenes (<C60) and Single-Walled Carbon Nanotubes,” Chem. Rev., Vol.105, No.10, pp.3643-3696 (2005).
[51] Zhou, O., R. M. Fleming, D. W. Murphy, C. H. Chen, R. C. Haddon, A. P. Ramirez, and S. H. Glarum, “Defects in Carbon Nanostructures,” Science, Vol.263, No.5154, pp.1744-1747 (1994).
[52] Martinez, J., and et al., “Length Control and Sharpening of Atomic Force Microscope Carbon Nanotube Tips Sssisted by an Electron Beam,” Nanotechnology, Vol.16, No.11, pp.2493 (2005).
[53] Lee, W. Y., C. C. Lin, K. S. Chang-Liao, K. C. Leou, and C. H. Tsai, “Electrical Characteristics of CNFETs with Asymmetric Gating Structures,” Diamond Relat. Mater., Vol.17, No.2, pp.154-157 (2008).
[54] Sarrazin, P., D. Blake, L. Delzeit, M. Meyyappan, B. Boyer, S. Snyder, and B. Espinosa, “Carbon Nanotube Field Emission X-ray Tube for Space Elploration XRD/XRF Instrument,” Adv. X-Ray Anal., Vol.47, pp.232-240 (2004).
[55] Iijima, S., and T. Ichihashi, “Single-Shell Carbon Nanotubes of 1-nm Diameter,” Nature, Vol.363, pp.603-605 (1993).
[56] Ebbesen, T. W., “Carbon Nanotubes,” Phys. Today, Vol.49, No.6, pp.26-32 (1996).
[57] Calderon Moreno, J. M., and M. Yoshimura, “Hydrothermal Processing of High-Quality Multiwall Nanotubes from Amorphous Carbon,” J. Am. Chem. Soc., Vol.123, No.4, pp.741-742 (2001).
[58] Ebbesen, T. W., H. J. Lezec, H. Hiura, J. W. Bennett, H. F. Ghaemi, and T. Thio, “Electrical Conductivity of Individual Carbon Nanotubes,” Nature, Vol.382, No.6586, pp.54-56 (1996).
[59] Vander Wal, R. L., T. M. Ticich, and V. E. Curtis, “Substrate-Support Interactions in Metal-Catalyzed Carbon Nanofiber Growth,” Carbon, Vol.39, No.15, pp.2277-2289 (2001).
[60] Jung, M., H. G. Kim, J. K. Lee, O. S. Joo, and S. i. Mho, “EDLC Characteristics of CNTs Grown on Nanoporous Alumina Templates,” Electrochim. Acta, Vol.50, No.2-3, pp.857-862 (2004).
[61] Bonard, J. M., J. P. Salvetat, T. S. ckli, W. A. d. Heer, L. s. Forro´, and A. C. telain, “Field Emission from Single-Wall Carbon Nanotube Films,” Appl. Phys. Lett., Vol.73, No.7, pp.918-920 (1998).
[62] Senda, S., Y. Sakai, Y. Mizuta, S. Kita, and F. Okuyama, “Super-Miniature X-ray Tube,” Appl. Phys. Lett., Vol.85, No.23, pp.5679-5681 (2004).
[63] Henry Huang, X. M., C. A. Zorman, M. Mehregany, and M. L. Roukes, “Nanoelectromechanical Systems: Nanodevice Motion at Microwave Frequencies,” Nature, Vol.421, No.6922, pp.496-496 (2003).
[64] Cheng, Y., and O. Zhou, “Electron Field Emission from Carbon Nanotubes,” C. R. Physique, Vol.4, No.9, pp.1021-1033 (2003).
[65] Troy, N.Y., “Beyond Batteries: Storing Power in a Sheet of Paper,” Eurekalert.org, http://www.eurekalert.org/pub_releases/2007-08/rpi-bbs080907.php.
[66] “New Flexible Plastic Solar Panels are Inexpensive and Easy to Make,” ScienceDaily, http://www.sciencedaily.com/releases/2007/07/070719011151.htm.
[67] Motta, M., A. Moisala, I. A. Kinloch, and A. H. Windle, “High Performance Fibres from ‘Dog Bone’ Carbon Nanotubes,” Adv. Mater., Vol.19, No.21, pp.3721-3726 (2007).
[68] Huang, S., and L. Dai, “Plasma Etching for Purification and Controlled Opening of Aligned Carbon Nanotubes,” J. Phys. Chem. B, Vol.106, No.14, pp.3543-3545 (2002).
[69] Borowiak-Palen, E., T. Pichler, X. Liu, M. Knupfer, A. Graff, O. Jost, W. Pompe, R. J. Kalenczuk, and J. Fink, “Reduced Diameter Distribution of Single-Wall Carbon Nanotubes by Eelective Oxidation,” Chem. Phys. Lett., Vol.363, No.5-6, pp.567-572 (2002).
[70] Chiang, I. W., B. E. Brinson, R. E. Smalley, J. L. Margrave, and R. H. Hauge, “Purification and Characterization of Single-Wall Carbon Nanotubes,” J. Phys. Chem. B, Vol.105, No.6, pp.1157-1161 (2001).
[71] Harutyunyan, A. R., B. K. Pradhan, J. Chang, G. Chen, and P. C. Eklund, “Purification of Single-Wall Carbon Nanotubes by Selective Microwave Heating of Catalyst Particles,” J. Phys. Chem. B, Vol.106, No.34, pp.8671-8675 (2002).
[72] Niu, C., E. K. Sichel, R. Hoch, D. Moy, and H. Tennent, “High Power Electrochemical Capacitors Based on Carbon Nanotube Electrodes,” Appl. Phys. Lett., Vol.70, No.11, pp.1480-1482 (1997).
[73] Geng, H. Z., K. K. Kim, K. P. So, Y. S. Lee, Y. Chang, and Y. H. Lee, “Effect of Acid Treatment on Carbon Nanotube-Based Flexible Transparent Conducting Films,” J. Am. Chem. Soc., Vol.129, No.25, pp.7758-7759 (2007).
[74] Yu, X., B. Lin, B. Gong, J. Lin, R. Wang, and K. Wei, “Effect of Nitric Acid Treatment on Carbon Nanotubes (CNTs)-Cordierite Monoliths Supported Ruthenium Catalysts for Ammonia Synthesis,” Catal. Lett., Vol.124, No.3, pp.168-173 (2008).
[75] Ci, L., H. Zhu, B. Wei, C. Xu, and D. Wu, “Annealing Amorphous Carbon Nanotubes for Their Application in Hydrogen Storage,” Appl. Surf. Sci., Vol.205, No.1-4, pp.39-43 (2003).
[76] Huang, W., Y. Wang, G. Luo, and F. Wei, “99.9% Purity Multi-Walled Carbon Nanotubes by Vacuum High-Temperature Annealing,” Carbon, Vol.41, No.13, pp.2585-2590 (2003).
[77] Garg, P., J. L. Alvarado, C. Marsh, T. A. Carlson, D. A. Kessler, and K. Annamalai, “An Experimental Study on the Effect of Ultrasonication on Viscosity and Heat Transfer Performance of Multi-Wall Carbon Nanotube-Based Aqueous Nanofluids,” Int. J. Heat Mass Transfer, Vol.52, No.21-22, pp.5090-5101 (2009).
[78] Thiên-Nga, L., K. Hernadi, E. Ljubović, S. Garaj, and L. Forró, “Mechanical Purification of Single-Walled Carbon Nanotube Bundles from Catalytic Particles,” Nano Lett., Vol.2, No.12, pp.1349-1352 (2002).
[79] Bandow, S., A. M. Rao, K. A. Williams, A. Thess, R. E. Smalley, and P. C. Eklund, “Purification of Single-Wall Carbon Nanotubes by Microfiltration,” J. Phys. Chem. B, Vol.101, No.44, pp.8839-8842 (1997).
[80] Niyogi, S., H. Hu, M. A. Hamon, P. Bhowmik, B. Zhao, S. M. Rozenzhak, J. Chen, M. E. Itkis, M. S. Meier, and R. C. Haddon, “Chromatographic Purification of Soluble Single-Walled Carbon Nanotubes (s-SWNTs),” J. Am. Chem. Soc., Vol.123, No.4, pp.733-734 (2001).
[81] Zhang, Y., X. Sun, L. Pan, H. Li, Z. Sun, C. Sun, and B. K. Tay, “Carbon Nanotube–Zinc Oxide Electrode and Gel Polymer Electrolyte for Electrochemical Supercapacitors,” J. Alloys Compd., Vol.480, pp.L17-L19 (2009).
[82] Li, J., X. Wang, Q. Huang, S. Gamboa, and P. J. Sebastian, “A New Type of MnO2•xH2O/CRF Composite Electrode for Supercapacitors,” J. Power Sources, Vol.160, No.2, pp.1501-1505 (2006).
[83] Chai, Y., L. G. Yu, M. S. Wang, Q. F. Zhang, and J. L. Wu, “Low-Field Emission from Iron Oxide-Filled Carbon Nanotube Arrays,” Chin. Phys. Lett., Vol.22, No.4, pp.911-914 (2005).
[84] Hsieh, C. T., Y. W. Chou, and W. Y. Chen, “Synthesis and Electrochemical Characterization of Carbon Nanotubes Decorated with Nickel Nanoparticles for use as an Electrochemical Capacitor,” J. Solid State Electrochem., Vol.12, No.6, pp.663-669 (2008).
[85] Pradeep, N., R. B. Sharma, and D. S. Joag, “Field Emission from a Nickel Adsorbed Tungsten Tip: Temperature Dependent Growth and its Effects on Current Stability,” Ultramicroscopy, Vol.73, pp.59-66 (1998).
[86] Shan, Y., and L. Gao, “Formation and Characterization of Multi-Walled Carbon Nanotubes/Co3O4 Nanocomposites for Supercapacitors,” Mater. Chem. Phys., Vol.103, No.2-3, pp.206-210 (2007).
[87] Wang, H., X. Quan, H. Yu, and S. Chen, “Fabrication of a TiO2/Carbon Nanowall Heterojunction and its Photocatalytic Ability,” Carbon, Vol.46, No.8, pp.1126-1132 (2008).
[88] Arabale, G., D. Wagh, M. Kulkarni, I. S. Mulla, S. P. Vernekar, K. Vijayamohanan, and A. M. Rao, “Enhanced supercapacitance of multiwalled carbon nanotubes functionalized with ruthenium oxide,” Chem. Phys. Lett., Vol.376, No.1-2, pp.207-213 (2003).
[89] Yu, H., X. Fu, C. Zhou, F. Peng, H. Wang, and J. Yang, “Capacitance Dependent Catalytic Activity of RuO2-xH2O/CNT Nanocatalysts for Aerobicoxidation of Benzyl Alcohol,” Chem. Commun., Vol.No.17, pp.2408-2410 (2009).
[90] Oke, S., M. Yamamoto, K. Shinohara, H. Takikawa, H. Xiaojun, S. Itoh, T. Yamaura, K. Miura, K. Yoshikawa, T. Okawa, and N. Aoyagi, “Specific Capacitance of Electrochemical Capacitor using RuO2 Loading arc-soot/Activated Carbon Composite Electrode,” Chem. Eng. J., Vol.146, No.3, pp.434-438 (2009).
[91] Jian Shan, Y., C. Hui Fang, L. Xiao, L. Tit Meng, Z. Wei De, and S. Fwu Shan, “Preparation and Characterization of Aligned Carbon Nanotube-Ruthenium Oxide Nanocomposites for Supercapacitors,” Small, Vol.1, No.5, pp.560-565 (2005).
[92] Bacsa, W. S., D. Ugarte, A. Châtelain, and W. A. de Heer, “High-Resolution Electron Microscopy and Inelastic Light Scattering of Purified Multishelled Carbon Nanotubes,” Phys. Rev. B, Vol.50, No.20, pp.15473-15476 (1994).
[93] Korotcov, A., H. P. Hsu, Y. S. Huang, and D. S. Tsai, “Raman Scattering Characterization of Well-Aligned IrO2 Nanocrystals Grown on Sapphire Substrates via Reactive Sputtering,” J. Raman Spectrosc., Vol.37, No.12, pp.1411-1415 (2006).
[94] Korotcov, A. V., Y. S. Huang, K. K. Tiong, and D. S. Tsai, “Raman Scattering Characterization of Well-Aligned RuO2 and IrO2 Nanocrystals,” J. Raman Spectrosc., Vol.38, No.6, pp.737-749 (2007).
[95] Katayama, M., K. Y. Lee, S. I. Honda, T. Hirao, and K. Oura, “Ultra-Low Threshold Filed Electron Emission from Pillar Array,” Jpn. J. Appl. Phys., Vol.43, pp.774-776 (2004).
[96] Calderon Moreno, J. M., and M. Yoshimura, “Hydrothermal Processing of High-Quality Multiwall Nanotubes from Amorphous Carbon,” J. Am. Chem. Soc., Vol.123, No.4, pp.741-742 (2001).
[97] Kyotani, T., L. F. Tsai, and A. Tomita, “Preparation of Ultrafine Carbon Tubes in Nanochannels of an Anodic Aluminum Oxide Film,” Chem. Mater., Vol.8, No.8, pp.2109-2113 (1996).
[98] Chen, C. A., Y. M. Chen, Y. S. Huang, D. S. Tsai, K. K. Tiong, and C. H. Du, “Growth and Characterization of V-Shaped IrO2 Nanowedges via Metal-Organic Vapor Deposition,” Nanotechnology, Vol.19, No.46, pp.465607 (2008).
[99] Gelb, L. D. and K. E. Gubbins, “Characterization of Porous Glasses: Simulation Models, Adsorption Isotherms, and the Brunauer−Emmett−Teller Analysis Method,” Langmuir, Vol.14, No.8, pp.2097-2111 (1998).
[100] Thanawala, S. S., R. J. Baird, D. G. Georgiev, and G. W. Auner, “Amorphous and Crystalline IrO2 Thin Films as Potential Stimulation Electrode Coatings,” Appl. Surf. Sci., Vol.254, No.16, pp.5164-5169 (2008).
[101] Liao, P. C., C. S. Chen, W. S. Ho, Y. S. Huang, and K. K. Tiong, “Characterization of IrO2 Thin Films by Raman Spectroscopy,” Thin Solid Films, Vol.301, No.1-2, pp.7-11 (1997).
[102] Chung, W. H., C. C. Wang, D. S. Tsai, J. C. Jiang, Y. C. Cheng, L. J. Fan, Y. W. Yang, and Y. S. Huang, “Deoxygenation of IrO2(1 1 0) Surface: Core-Level Spectroscopy and Density Functional Theory Calculation,” Surf. Sci., Vol.604, No.2, pp.118-124 (2010).
[103] Gladys, M. J., I. Ermanoski, G. Jackson, J. S. Quinton, J. E. Rowe, and T. E. Madey, “A High Resolution Photoemission Study of Surface Core-Level Shifts in Clean and Oxygen-Covered Ir(2 1 0) Surfaces,” J. Electron. Spectrosc. Relat. Phenom., Vol.135, No.2-3, pp.105-112 (2004).
[104] Wertheim, G. K., and H. J. Guggenheim, “Conduction-electron Screening in Metallic Oxides: IrO2,” Phys. Rev. B, Vol.22, No.10, pp.4680 (1980).
[105] da Silva, L. A., V. A. Alves, S. C. de Castro, and J. F. C. Boodts, “XPS Study of the State of Iridium, Platinum, Titanium and Oxygen in Thermally Formed IrO2+TiO2+PtOX Films,” Colloids Surf., A, Vol.170, No.2-3, pp.119-126 (2000).
[106] Temple, D., “Recent Progress in Field Emitter Array Development for High Performance Applications,” Mater. Sci. Eng., R, Vol.24, No.5, pp.185-239 (1999).
[107] Korotcov, A., Y. S. Huang, T. Y. Tsai, D. S. Tsai, and K. K. Tiong, “Effect of Length, Spacing and Morphology of Vertically Aligned RuO2 Nanostructures on Field-Emission Properties,” Nanotechnology, Vol.17, No.13, pp.3149-3153 (2006).
[108] Zhao, Q., H. Z. Zhang, Y. W. Zhu, S. Q. Feng, X. C. Sun, J. Xu, and D. P. Yu, “Morphological Effects on the Field Emission of ZnO Nanorod Arrays,” Appl. Phys. Lett., Vol.86, No.20, pp.203115 (2005).
[109] Ago, H., T. Kugler, F. Cacialli, W. R. Salaneck, M. S. P. Shaffer, A. H. Windle, and R. H. Friend, “Work Functions and Surface Functional Groups of Multiwall Carbon Nanotubes,” J. Phys. Chem. B, Vol.103, No.38, pp.8116-8121 (1999).
[110] Hirayama, H., Y. Kawamoto, Y. Ohshima, and K. Takayanagi, “Nanospot Welding of Carbon Nanotubes,” Appl. Phys. Lett., Vol.79, No.8, pp.1169-1171 (2001).
[111] Lyth, S. M., R. A. Hatton, and S. R. P. Silva, “Efficient Field Emission from Li-Salt Functionalized Multiwall Carbon Nanotubes on Flexible Substrates,” Appl. Phys. Lett., Vol.90, No.1, pp.013120-013123 (2007).
[112] Machida, H., S. I. Honda, S. Fujii, K. Himuro, H. Kawai, K. Ishida, K. Oura, and M. Katayama, “Effect of Electrical Aging on Field Electron Emission from Screen-Printed Carbon Nanotube Film,” Jpn. J. Appl. Phys., Vol.46, pp.867-869 (2007).
[113] Monica, A. H., M. Paranjape, G. L. Coles, S. J. Papadakis, and R. Osiander, “Toward a Lateral Carbon Nanotube Based Field Emission Triode,” J. Vac. Sci. Technol. B, Vol.26, No.2, pp.838-841 (2008).
[114] Nilsson, L., O. Groening, C. Emmenegger, O. Kuettel, E. Schaller, L. Schlapbach, H. Kind, J. M. Bonard, and K. Kern, “Scanning Field Emission from Patterned Carbon Nanotube Films,” Appl. Phys. Lett., Vol.76, No.15, pp.2071-2073 (2000).
[115] Fujii, S., S. I. Honda, H. Machida, H. Kawai, K. Ishida, M. Katayama, H. Furuta, T. Hirao, and K. Oura, “Efficient Field Emission from an Individual Aligned Carbon Nanotube Bundle Enhanced by Edge Effect,” Appl. Phys. Lett., Vol.90, No.15, pp.153108-153103 (2007).
[116] Yu, K., Y. S. Zhang, F. Xu, Q. Li, Z. Q. Zhu, and Q. Wan, “Significant Improvement of Field Emission by Depositing Zinc Oxide Nanostructures on Screen-Printed Carbon Nanotube Films,” Appl. Phys. Lett., Vol.88, No.15, pp.153123-153123 (2006).
[117] Chakrabarti, S., L. Pan, H. Tanaka, S. Hokushin, and Y. Nakayama, “Stable Field Emission Property of Patterned MgO Coated Carbon Nanotube Arrays,” Jpn. J. Appl. Phys., Vol.46, No.7A, pp.4364-4369 (2007).
[118] Ramasubramanian, N., N. Preocanin, and R. D. Davidson, “Analysis of Passive Films on Stainless Steel by Cyclic Voltammetry and Auger Spectroscopy,” J. Electrochem. Soc., Vol.132, No.4, pp.793-798 (1985).
[119] Toupin, M., T. Brousse, and D. Bélanger, “Charge Storage Mechanism of MnO2 Electrode Used in Aqueous Electrochemical Capacitor,” Chem. Mater., Vol.16, No.16, pp.3184-3190 (2004).
[120] Barbieri, O., M. Hahn, A. Foelske, and R. Kotz, “Effect of Electronic Resistance and Water Content on the Performance of RuO2 for Supercapacitors,” J. Electrochem. Soc., Vol.153, No.11, pp.A2049-A2054 (2006).
[121] Kuratani, K., H. Tanaka, T. Takeuchi, N. Takeichi, T. Kiyobayashi, and N. Kuriyama, “Binderless Fabrication of Amorphous RuO2 Electrode for Electrochemical Capacitor using Spark Plasma Sintering Technique,” J. Power Sources, Vol.191, No.2, pp.684-687 (2009).
[122] Susanti, D., D. S. Tsai, and Y. S. Huang, “Hybrid Electrochemical Capacitor of IrO2 Nanocrystal and Hydrous RuO2,” Science of Advanced Materials, Vol.2, pp.552-559 (2010).
[123] Sugimoto, W., H. Iwata, K. Yokoshima, Y. Murakami, and Y. Takasu, “Proton and Electron Conductivity in Hydrous Ruthenium Oxides Evaluated by Electrochemical Impedance Spectroscopy:  The Origin of Large Capacitance,” J. Phys. Chem. B, Vol.109, No.15, pp.7330-7338 (2005).
[124] Pajkossy, T., L. A. Kibler, and D. M. Kolb, “Voltammetry and Impedance Measurements of Ir(1 1 1) Electrodes in Aqueous Solutions,” J. Electroanal. Chem., Vol.582, No.1-2, pp.69-75 (2005).
[125] Pajkossy, T., L. A. Kibler, and D. M. Kolb, “Voltammetry and Impedance Measurements of Ir(1 0 0) Electrodes in Aqueous Solutions,” J. Electroanal. Chem., Vol.600, No.1, pp.113-118 (2007).
[126] Gómez, R., and M. J. Weaver, “Reduction of Nitrous Oxide on Iridium Single-Crystal Electrodes,” Langmuir, Vol.18, No.11, pp.4426-4432 (2002).
[127] Yu, A., I. Roes, A. Davies, and Z. Chen, “Ultrathin, Transparent, and Flexible Graphene Films for Supercapacitor Application,” Appl. Phys. Lett., Vol.96, No.25, pp.253105-253103 (2010).
[128] Chen, Y. M., J. H. Cai, Y. S. Huang, K. Y. Lee, and D. S. Tsai, “Preparation and Characterization of Iridium Dioxide–Carbon Nanotube Nanocomposites for Supercapacitors,” Nanotechnology, Vol.22, No.11, pp.115706 (2011).