本研究主要目的在於開發新對電極製程以取代濺鍍法所製備之白金對電極，研究內容主要分為兩個部分：(1)利用刮刀塗佈法製備碳黑對電極，(2)醇類還原法製備白金/碳黑複合對電極。第一部分的實驗結果顯示在350℃熱處理下，對電極中碳黑含量從8wt%增加至15wt%時可提升碳黑對電極的電化學活性，並且降低碳黑/電解質之界面電荷轉移阻力(Rct)至6.65 ohm x cm2，應用於元件之最佳效率為6.68%。若將熱處理溫度上升至450℃去除對電極中的PVDF後，相較於350℃熱處理而言，碳黑對電極對於I-/I3-的電化學活性明顯提升，碳黑/電解質之界面電荷轉移阻力可下降至0.44 ohm x cm2，應用於元件可使效率提升至8.35%，接近白金電極的元件效率8.38%。第二部分的實驗結果顯示利用醇類還原法可製備大小為2~5nm的白金粒子於碳黑表面。將白金/碳黑觸媒製備成對電極可發現增加觸媒層數可提升對電極的電化學活性，降低對電極/電解質的Rct。此外降低黏著劑含量可提升對電極對I-/I3-的電性表現，其結果顯示在低黏著劑含量下，對電極/電解質的Rct可下降至1.44 ohm x cm2，應用於元件其效率可達8.06%，接近白金電極的元件效率8.17%。

The main purpose of this study is to replace platinum counter electrode prepared by sputter technique. This research includes two parts: (1) Fabrication of carbon black counter electrodes by doctor blading and (2) Preparation of platinum/carbon black (Pt/CB) counter electrodes by polyol reduction.
In part.1, the results show that under 350oC heat treatment, the performance of carbon black counter electrodes has strong relationship with carbon black content. Increasing the carbon black content from 8wt% to 15wt% can enhance the electro-activity of counter electrodes, and reduce the charge transfer resistance (Rct) between carbon black/electrolyte interface to 6.65 ohm x cm2. Under this heat treatment condition, the best power conversion efficiency is 6.68%. Compared to the results obtained under 350 oC heat treatment, elevating heat treated temperature to 450 oC can improve electro-activity of counter electrodes significantly, and decrease Rct to 0.44 ohm x cm2. Applying the carbon counter electrodes on DSSC, the best power conversion efficiency 8.35% can be achieved, which is comparable to 8.38% cell efficiency obtained by using sputtered-Pt as counter electrode.
In part.2, the results show that the size of platinum nanoparticles synthesized on carbon black by polyol reduction is 2~5nm. Increasing the number of Pt/CB layer can enhance the electro-activity of Pt/CB composite counter electrodes, and decrease the charge transfer resistance at the electrode/electrolyte interface. Besides, reducing the binder concentration of the paste has positive effects on counter electrode performance. Appling the Pt/CB counter electrodes containing low binder concentration, the low Rct 1.44 ohm x cm2 can be obtained, and the best cell efficiency 8.06% can be achieved, which is close to 8.17% by using sputtered-Pt as counter electrode.

[1] M. Grätzel, "Power the Plant," Nature, vol. 403, p. 363, 2000.
[2] H. Tsubomura, M. Matsumura, and Y. Nomura, "Dye Sensitized Zinc Oxide : Aqueous Electrolyte : Platinum Photocell," Nature, vol. 261, p. 402 , 1976.
[3] B. O'Regan and M. Grätzel, "A Low-cost, High-efficiency Solar Cell Based on Dye-sensitized Colloial TiO2 Films," Letter to nature, vol. 353, p. 737, 1991.
[4] M. Grätzel, "Photoelectrochemical cells," Nature, vol. 414, p. 338, 2001.
[5] M. Grätzel, "Conversion of sunlight to electric power by nanocrystalline dye-sensitized solar cells," Journal of Photochemistry and Photobiology A: Chemistry, vol. 164,p. 3, 2004.
[6] X. Feng, K. Shankar, O. K. Varghese, M. Paulose, T. J. Latempa, and Craig A. Grimes, "Vertically Aligned Single Crystal TiO2 Nanowire Arrays Grown Directly on Transparent Conducting Oxide Coated Glass: Synthesis Details and Applications, " Nano Letters,vol. 8, p. 3781, 2008.
[7] O. K. Varghese, M. Paulose, and Craig A. Grimes, "Long vertically aligned titania nanotubes on transparent conducting oxide for highly efficient solar cells, " nature nanotechnology, vol. 4, p. 592, 2009.
[8] W. Shockley and H. J. Queisser, "Detailed Balance Limit of Efficiency of p-n Junction Solar Cells, " J. Appl. Phys., vol. 32,p. 510, 1961.
[9] M. Grätzel, "Recent Advances in Sensitized Mesoscopic Solar Cells," ACCOUNTS of chemical research, vol. 42, p. 11, 2009.
[10] M. K. Nazeeruddin, A. Kay, I. Rodicio, R. Humpbry-Baker, E. Miiller, P. Liska, N. Vlachopoulos, and M. Gratzel, "Conversion of Light to Electricity by cis-XzBis( 2,2’-bipyridyl-4,4’-dicarboxylate)ruthenium (II) Charge-Transfer Sensitizers (X = C1-, Br-, I-, CN-, and SCN-) on Nanocrystalline TiO2 Electrodes," Journal of American Chemical Society,vol. 115,p. 6382, 1993.
[11] M. K. Nazeeruddin, P. Péchy, and M. Grätzel, "Efficient panchromatic sensitization of nanocrystalline TiO2 films by a black dye based on a trithiocyanato–ruthenium complex," Chemical. Communication.,vol. 18, p. 1705, 1997.
[12] M. Grätzel, "Engineering of Efficient Panchromatic Sensitizers for Nanocrystalline TiO2-Based Solar Cells," Journal of American Chemical Society, vol. 123, p. 1613, 2001.
[13] M. Grätzel, "Combined Experimental and DFT-TDDFT Computational Study of Photoelectrochemical Cell Ruthenium Sensitizers," Journal of American Chemical Society, vol. 127, p. 16835, 2005.
[14] P. Wang, S. M. Zakeeruddin, J. E. Moser, M. K. Nazeeruddin, T. Sekiguchi and M. Grätzel, "A stable quasi-solid-state dye-sensitized solar cell with an amphiphilic ruthenium sensitizer and polymer gel electrolyte, "Nature Materials,vol. 2, p. 402, 2003.
[15] Y. Liu, J. R. Jennings, Y. Huang, Q. Wang, S. M. Zakeeruddin, and M. Grätzel, "Cobalt Redox Mediators for Ruthenium-Based Dye-Sensitized Solar Cells: A Combined Impedance Spectroscopy and Near-IR Transmittance Study, " Journal of Physical Chemistry C, vol. 115, p. 18847, 2011.
[16] C.-Y. Chen, M. Wang, J.-Y. Li, N. Pootrakulchote, L. Alibabaei, C.-h. Ngoc-le, J.-D. Decoppet, J.-H. Tsai, C. Grätzel, C.-G. Wu, S. M. Zakeeruddin and M. Grätzel, "Highly Efficient Light-Harvesting Ruthenium Sensitizer for Thin-Film Dye-Sensitized Solar Cells, "ACS Nano, vol. 3, p. 3103, 2009.
[17] Q. Yu, Y. Wang, Z. Yi, N. Zu, J. Zhang, M. Zhang and P. Wang, "High-Efficiency Dye-Sensitized Solar Cells: The Influence of Lithium Ions on Exciton Dissociation, Charge Recombination, and Surface States, "ACS Nano,vol. 4 , p. 6032, 2010.
[18] T. Bessho, S. M. Zakeeruddin, C.-Y. Yeh, E. W.-G. Diau, and M. Grätzel, "Highly Efficient Mesoscopic Dye-Sensitized Solar Cells Based on Donor–Acceptor-Substituted Porphyrins, "Angewandte Chemie International Edition, vol. 49, p. 6646, 2010.
[19] A. Yella, H.-W. Lee, H. N. Tsao, C. Yi, A. K. Chandiran, M. K. Nazeeruddin, E. W.-G. Diau, C.-Y. Yeh, S. M. Zakeeruddin, M. Grätzel, "Porphyrin-Sensitized Solar Cells with Cobalt (II/III)–Based Redox Electrolyte Exceed 12 Percent Efficiency, " Science, vol. 334, p. 629, 2011.
[20] S. Mathew, A. Yella, P. Gao, R. H.-Baker, B. F. E. Curchod, N. A.- Astani, I. Tavernall, U. Rothlisberger, M. K. Nazeeruddin and M. Grätzel,"Dye-sensitized solar cells with 13% efficiency achieved through the molecule engineering of porphyrin sensitizers, " Nature Chemistry ,vol. 6,p. 242, 2014.
[21] S. Ito, S. M. Zakeeruddin, R. H.-Baker, P. Liska, R. Charvet, P. Comte, M. K. Nazeeruddin, P. Péchy, M. Takata, H. Miura, S. Uchida, and Michael Grätzel, "High-Efficiency Organic-Dye-Sensitized Solar Cells Controlled by Nanocrystalline-TiO2 Electrode Thickness, "Advanced Material, vol. 18, p. 1202, 2006.
[22] S. Ito, H. Miura, S. Uchida, M. Takata, K. Sumioka, P. Liska, P. Comte, P. Péchy and M. Grätzel, "High-conversion-efficiency Organic Dye-sensitized Solar Cells with A Novel Indoline Dye," Chemical Communication, vol. 41, p. 5194, 2008.
[23] G. Zhang, H. Bala, Y. Cheng, D. Shi, X. Lv, Q. Yu and P. Wang, "High efficiency and stable dye-sensitized solar cells with an organic chromophore featuring a binary π-conjugated spacer," Chemical Communication, vol. 16, p. 2198, 2009.
[24] W. Zeng, Y. Cao, Y. Bai, Y. Wang, Y. Shi, M. Zhang, F. Wang, C. Pan and P. Wang, "Efficient Dye-Sensitized Solar Cells with an Organic Photosensitizer Featuring Orderly Conjugated Ethylenedioxythiophene and Dithienosilole Blocks," Chemistry of Materials ,vol. 22, p. 1915, 2010.
[25] G. Wolbauer, A. M. Bond and J. C. Eklund, "A Channel Flow Cell System Specifically Designed to Test the Efficiency of Redox Shuttles in Dye Sensitized Solar Cells," Solar Energy Materials & Solar Cells, vol. 70, p. 85, 2001.
[26] C. A. Kelly, F. Farzad, D. W. Thompson, J. M. Stipkala and G. J. Meyer,"Cation-Controlled Interfacial Charge Injection in Sensitized Nanocrystalline TiO2," Langmuir, vol. 15, p. 7047, 1999.
[27] Yao Liu, A. Hagfeldt, X.-R. Xiao, S.-E. Lindquist,"Investigation of influence of redox species on the interfacial energetics of a dye-sensitized nanoporous TiO2 solar cell," Solar Energy Materials & Solar Cells, vol. 55, p. 267, 1998.
[28] S. Pelet, J.-E. Moser and M. Grätzel, "Cooperative Effect of Adsorbed Cations and Iodide on the Interception of Back Electron Transfer in the Dye Sensitization of Nanocrystalline TiO2, " Journal of Physical Chemistry B, 104, 1791, 2000.
[29] S. Kambe, S. Nakade, T. Kitamura,Y. Wada and S. Yanagida, "Influence of the Electrolytes on Electron Transport in Mesoporous TiO2-Electrolyte Systems, " Journal of Physical Chemistry B, vol. 106, p. 2967, 2002.
[30] P. Wang, S. M. Zakeeruddin, I. Exnar and M. Grätzel, "High efficiency dye-sensitized nanocrystalline solar cells based on ionic liquid polymer gel electrolyte, " Chemical Communication, vol. 24, p. 2972, 2002.
[31] W. Kubo, T. Kitamura, K. Hanabusa, Y. Wada and S. Yanagida, "Quasi-solid-state dye-sensitized solar cells using room temperature molten salts and a low molecular weight gelator, " Chemical Communication, vol. 4, p. 374, 2002.
[32] N. Mohmeyer, D. Kuang, P. Wang, H.-W. Schmidt, S. M. Zakeeruddin and M. Grätzel, "An efficient organogelator for ionic liquids to prepare stable quasi-solid state dye-sensitized solar cells, "Journal of Materials Chemistry, vol. 16, p. 2978, 2006.
[33] R. Komiya, L. Han, R. Yamanaka, A. Islam, T. Mitate, "Highly efficient quasi-solid state dye-sensitized solar cell with ion conducting polymer electrolyte, "Journal of Photochemistry and Photobiology A: Chemistry, vol. 164, p. 123, 2004.
[34] F. Sauvage, S. Chhor, A. Marchioro, J.-E. Moser and M. Grätzel, "Butyronitrile-Based Electrolyte for Dye-Sensitized Solar Cells, " Journal of American Chemical Society, vol. 133, p. 13013, 2011.
[35] T. W. Hamann, "The end of iodide? Cobalt complex redox shuttles in DSSCs, "Dalton Transaction, vol. 41, p. 3111, 2012.
[36] S. M. Feldt, G. Wang, G. Boschloo and A. Hagfeldt, "Effects of Driving Forces for Recombination and Regeneration on the Photovoltaic Performance of Dye-Sensitized Solar Cells using Cobalt Polypyridine Redox Couples, " Journal of Physical Chemistry C, vol. 115, p. 21500, 2011.
[37] C. H. Yoon, R. Vittal, J. Lee, W.-S. Chae, K.-J. Kim, "Enhanced performance of a dye-sensitized solar cell with an electrodeposited-platinum counter electrode, "Electrochimica Acta, vol. 53, p. 2890, 2008.
[38] L.-L. Li, C.-W. Chang, H.-H. Wu, J.-W. Shiu, P.-T. Wu and E. W.-G. Diau, "Morphological control of platinum nanostructures for highly efficient dye-sensitized solar cells, " Journal of Materials Chemistry, vol. 22, p. 6267, 2012.
[39] Y.-L. Lee, C.-L. Chen, L.-W. Chong, C.-H. Chen, Y.-F. Liu, C.-F. Chi, "
A platinum counter electrode with high electrochemical activity and high
transparency for dye-sensitized solar cells," Electrochemistry Communications, vol. 12, p. 1662, 2010.
[40] N. Papageorgiou, W. F. Maier and M. Grätzel, "An Iodine/Triiodide Reduction Electrocatalyst for Aqueous and Organic Media, " Journal of The Electrochemical Society, vol. 144, p. 876, 1997.
[41] K. Imoto, K. Takahashi, T. Yamaguchi, T. Komura, J.-I. Nakamura, K. Murata, "High-performance carbon counter electrode for dye-sensitized solar cells, " Solar Energy Materials & Solar Cells, vol. 79, p. 459, 2003.
[42] T. N. Murakami, S. Ito, Q. Wang, M. K. Nazeeruddin, T. Bessho, I. Cesar, P. Liska, R. H. - Baker, P. Comte, P. Péchy and M. Grätzel, "Highly Efficient Dye-Sensitized Solar Cells Based on Carbon Black Counter Electrodes, " Journal of The Electrochemical Society, vol. 153, p. A2255, 2006.
[43] P. Joshi, Y Xie, M. Ropp, D. Galipeau, S. Bailey and Q. Qiao, "Dye-sensitized solar cells based on low cost nanoscale carbon/TiO2 composite counter electrode, " Energy & Environmental Science, vol. 2, p. 426, 2009.
[44] E. Ramasamy, W. J. Lee, D. Y. Lee, J. S. Song, "Spray coated multi-wall carbon nanotube counter electrode for tri-iodide (I3-) reduction in dye-sensitized solar cells, " Electrochemistry Communications, vol. 10, p. 1087, 2008.
[45] W. J. Lee, E. Ramasamy, D. Y. Lee, J. S. Song, "Efficient Dye-Sensitized Solar Cells with Catalytic Multiwall Carbon Nanotube Counter Electrodes, "ACS Applied Materials & Interfaces, vol. 1, p. 1145, 2009.
[46] J. D. R.-Mayhew, D. J. Bozym, C. Punckt, and I. A. Aksay, "Functionalized Graphene as a Catalytic Counter Electrode in Dye-Sensitized Solar Cells, " ACS Nano, vol. 4, p. 6203, 2010.
[47] H. Choi, H. Kim, S. Hwang, Y. Han and M. Jeon, "Graphene counter electrodes for dye-sensitized solar cells prepared by electrophoretic deposition, " Journal of Materials Chemistry, vol. 21, p.7548, 2011.
[48] H.-S. Jang, J.-M. Yun, D.-Y. Kim, D.-W. Park, S.-I. Na, S.-S. Kim, "Moderately reduced graphene oxide as transparent counter electrodes for dye-sensitized solar cells, " Electrochemical Acta, vol. 81, p. 301, 2012.
[49] M. Wang, A. M. Anghel, B. Marsan, N.-L. C. Ha, N. Pootrakulchote, S. M. Zakeeruddin and M. Grätzel, "CoS Supersedes Pt as Efficient Electrocatalyst for Triiodide Reduction in Dye-Sensitized Solar Cells, " Journal of American Chemical Society, vol. 131, p. 15976, 2009.
[50] Q. W. Jiang, G. R. Li and X. P. Gao, "Highly ordered TiN nanotube arrays as counter electrodes for dye-sensitized solar cells," Chemical Communication, issue 44, p.6720, 2009.
[51] M. Wu, X. Lin, Y. Wang, L. Wang, W. Guo, D. Qi, X. Peng, A. Hagfeldt, M. Grätzel and T. Ma, "Economical Pt-Free Catalysts for Counter Electrodes of Dye-Sensitized Solar Cells," Journal of American Chemical Society, vol. 134, p. 3419, 2012.
[52] J. M. Pringle, V. Armel and D. R. MacFarlane, "Electrodeposited PEDOT-on-plastic cathodes for dye-sensitized solar cells," Chemical Communication, vol. 46, p. 5367, 2010.
[53] J. Wu, Q. Li, L. Fan, Z. Lan, P. Li, J. Lin, and S. Hao, "High-performance polypyrrole nanoparticles counter electrode for dye-sensitized solar cells, "Journal of Power Sources, vol. 181, p.172, 2008.
[54] Q. Tai, B. Chen, F. Guo, S. Xu, H. Hu, B. Sebo, and X.-Z. Zhao, "In Situ Prepared Transparent Polyaniline Electrode and Its Application in Bifacial Dye-Sensitized Solar Cells, " ACS Nano, vol. 5, p. 3795, 2011.
[55] P. Li, J. Wu, J. Lin, M. Huang, Y. Huang and Q. Li, "High-performance and low platinum loading Pt/Carbon black counter electrode for dye-sensitized solar cells, " Solar Energy, vol. 83, p. 845, 2009.
[56] K.-C. Huang, Y.-C. Wang, R.-X. Dong, W.-C. Tsai, K.-W. Tsai, C.-C. Wang, Y.-H. Chen, R. Vittal, J.-J. Lin and K.-C. Ho, "A high performance dye-sensitized solar cell with a novel nanocomposite film of PtNP/MWCNT on the counter electrode," Journal of Materials Chemistry, vol. 20, p. 4067, 2010.
[57] M.-Y. Yen, C.-C. Teng, M.-C. Hsiao, P.-I. Liu, W.-P. Chuang, C.-C. M. Ma, C.-K. Hsieh, M.-C. Tsai and C.-H. Tsai, "Platinum nanoparticles/graphene composite catalyst as a novel composite counter electrode for high performance dye-sensitized solar cells, " Journal of Materials Chemistry, vol. 21, p. 12880, 2011.
[58] G.R. Li, F. Wang, J. Song, F.Y. Xiong and X.P. Gao, "TiN-conductive carbon black composite as counter electrode for dye-sensitized solar cells, "Electrochimica Acta, vol. 65, p. 216, 2012.
[59] X. Miao, K. Pan, Q. Pan, W. Zhou, L. Wang, Y. Liao, G. Tian and G. Wang, "Highly crystalline graphene/carbon black composite counter electrodes with controllable content: Synthesis, characterization and application in dye-sensitized solar cells, " Electrochimica Acta, vol.96, p. 155, 2013.