本研究提出了「還原的氧化石墨烯」橋接於二氧化鈦之間，應用於染料敏化太陽電池的光電轉換效率之提升。本研究先探討氧化石墨烯之備製，基於安全的Hummers濕式備置方法具有優良的氧化石墨烯結構，一直以來被普遍使用，所以，本研究採用其方法，並改變不同的合成條件，期能備製出最佳結晶性及產量的氧化石墨烯。各樣本經一系列的分析工具評估，其中包含產量，微觀結構，表面化學分析，以及光學穿透率的特點。合成條件是以不同配方之濃度重量百分比，添加至化學懸浮液中，經本研究證實，可獲得極少層的氧化石墨烯，並表現出良好的結晶性。重要發現為產量的多寡與 NaNO3/ KMnO4 比例有因果關係。再則，經結晶性分析工具分析亦可發現，不同合成參數的組合，備製出來的樣本，除了其結晶大小略為不同外，其拉曼分析之結晶性及半高寬並無明顯不同，其結晶性良好。應用產出的氧化石墨烯塗佈成透明薄膜，已獲得光穿透率可超過80%。
由於石墨烯極低電阻的特性，本研究應用「還原的氧化石墨烯」橋接於二氧化鈦顆粒間，以提升染料敏化太陽電池之效能。因疏水性的碳材不易均勻地分佈在水性溶液中，本研究使用氧化石墨烯，可充分地分散於二氧化鈦之膠態水溶液中，備製二氧化態光電極後，在燒結過程中氧化石墨烯在高溫下還原成石墨烯，此極薄的碳膜，在二氧化鈦顆粒間形成導電性極佳的橋樑。在實驗中，我們發現石墨烯的確可以使太陽電池的效能由5.34%提升至5.95%，計提升了11.4 %。此外，電子在光電極擴散至對電極的時間從4.74微秒縮短至3.63微秒，速度加快約23.4%，被激發的光電子的電子壽命從19.58微秒延長至27.85微秒， 提升約42.3%。
基於可攜式之穿戴式裝置的流行，本研究以鈦箔基板為光陽極，鍍有一層白金的氧化銦錫塗覆的基板作為對電極，完成「完全可撓式染料敏化太陽電池」(FDSC)。在本研究中，FDSC使用兩種類型的光電極的二氧化鈦(TiO2)材料，分別為商用的TiO2顆粒(P25)和本研室自製的TiO2球珠二種，光電極中，亦混入自製的氧化石墨烯，在光電極燒結過程中，還原成石墨烯分佈在光陽極中，增加光電極的導電性。此外， TiO2緻密層(CL)亦應用於鈦基板上。 CL，石墨烯，以及介孔洞TiO2球珠的使用與否的成效在本研究中提出並討論之，其優化了可撓式染料敏化太陽電池，與未使用之原樣本比較，效率改善高達154％。最後，為了更進一步改善染料敏化太陽電池的光電極中「還原的氧化石墨烯」的效能，使用紫外線輔助「再加強地」還原之石墨烯之導電性，在研究探討中，分成兩種處理方式，一為先照紫外光預還原，再以焙燒。另一種方法，先焙燒之後，再照紫外光再加強還原之。其目的是藉由紫外光的輔助，加強地還原的氧化石墨烯。經過紫外線輔助還原處理，石墨烯對光電陽極性能提升，進而對太陽電池性能提升，並獲得電池效率達8.24％的增幅。

Dye-sensitized solar cells containing reduced graphene oxide for enhancing performance was discussed and proved its profits. Various graphene oxide (GO) samples were prepared using the Hummers method under different synthesis conditions. The obtained GO samples were evaluated for the yields and characterized for the microstructure, surface chemistry, and optical transmittance. The effects of the chemical concentrations, and the addition rates of the chemical and water on the yields and characteristics are reported. The GOs obtained consist of a few layers and exhibit good crystallinity. It was found that the yield was mainly affect by the water dropping rate as well as the NaNO3/KMnO4 ratio. Also the resulting GOs are quite similar, regardless of the synthesis conditions, except that the graphite clusters vary slightly in their sizes. GO coatings exhibit optical transmittance greater than 80% has been obtained. Furthermore, the use of reduced GO (RGO) to bridge TiO2 particles in the photoanode of dye-sensitized solar cell (DSC) for reduced electrical resistance has been investigated. The difficulty in dispersing RGO in TiO2 paste was overcome by first dispersing GO into the TiO2 paste. The GO was then reduced to RGO after the sintering of TiO2. Depending on the amount of RGO in the photoanode, the cell performance was enhanced to different degrees. A maximum increase of 11.4 % in the cell efficiency has been obtained. In particular, the inclusion of graphene has reduced the electron diffusion time by as much as 23.4%, i.e., from 4.74 to 3.63 ms and increased the electron lifetime by as much as 42.3%, i.e., from 19.58 to 27.85 ms. In order to fabricate true flexible DSC (FDSC) using Titanium (Ti) foil and indium tin oxide coated polyethylene naphthalate as the substrates for the photoanode and the counter electrode, respectively. Two types of TiO2 powders were used for making the photoanodes, namely, commercial TiO2 particles (P25) and homemade TiO2 mesoporous beads. RGO was included in selected photoanodes to improve the electrical conductivity. The fabricated cells have either a TiO2 compact layer (CL) or not. The effects of CL, RGO addition, and the use of mesoporous TiO2 beads on the cell performance are presented and discussed. We demonstrated that the optimized use of CL, RGO, and the beads improve the efficiency by as much as 154 %. On the other hand, the use of RGO connect between TiO2 particles in DSCs photoanaodes for reducing electrical resistance using heat treatment and ultraviolet(UV)-assisted reduction for GO has been investigated. Before or after the calcination, a UV-assisted reduction process was applied to remove the residuals in the photoanodes. The photoelectrodes were then employed to make DSCs. Depending on UV-assisted reduction treatment, the cell performance was enhanced to various degrees. A maximum increase of 8.24 % in the cell efficiency has been obtained. Effects of graphene addition and the UV treatment on the characteristics of the photoanodes properties and the photovoltaic performances are discussed. The resulting photoanodes were characterized using X-ray photoelectron spectroscopy (XRD), Raman microscopy, scanning electron microscopy (SEM), X-Ray Photoemission Spectroscopy (XPS), transmission electron microscopy (TEM), and UV-vis-NIR optical spectroscopy. Cell performance was evaluated using a solar simulator, incident photon to electron conversion efficiency (IPCE), and electrochemical impedance spectroscopy (EIS). These shows DSCs containing RGO were applied for enhancing performance.

1. M.A. Green, K. Emery, Y. Hishikawa, Wilhelm Warta and Ewan D. Dunlop, Solar cell efficiency tables (version 44), Prog. Photovoltaics Res. Appl. 2014. 22: p. 701-710
2. B. O'Regan, M. Gratzel, A low-coat, high-efficiciency solar cell based on dye-sensitized colloidal TiO2 films, Nature 1991. 353: p. 737-740.
3. B. C. Brodie, On the Atomic Weight of Graphite, Philos. Trans. R. Soc. London 1859. 149: p. 249-259
4. I. Dékány, R. Krüger-Grasser, A.Weiss, Selective liquid sorption properties of hydrophobized GO nanostructures, Colloid. Polym. Sci. 1998. 276: p. 570-576
5. A. Bourlinos, D. Gournis, D. Petridis, T. Szabó, A. Szeri, I. Dékány, Graphite Oxide: Chemical Reduction to Graphite and Surface Modification with Primary Aliphatic Amines and Amino Acidsk, Langmuir 2003. 19: p. 6050-6055
6. T. Szabó, A. Szeri, I. Dékány, Composite graphitic nanolayers prepared by self-assembly between finely dispersed graphite oxide and a cationic polymer, Carbon 2005. 43: p. 87-94
7. T. Szabó, E. Tombácz, E. Illés, I. Dékány, Enhanced acidity and pH-dependent surface charge characterization of successively oxidized graphite oxides, Carbon 2006. 44: p. 537-545
8. L. Staudenmaier, Verfahren zur Darstellung der Graphitsäure, Chem. Ges. 1898, 31: p. 1481
9. H.C. Schniepp, J.L. Li, M.J. McAllister, H. Sai, M. Herrera-Alonso, D.H. Adamson, R.K. Prud’homme, R. Car, D.A. Saville, I.A. Aksay, Functionalized Single Graphene Sheets Derived from Splitting Graphite Oxide, J. Phys. Chem. B 2006. 110(17): p. 8535-8539
10. G. Wang, B. Wang, J. Park, J. Yang, X. Shen, J. Yao, Synthesis of enhanced hydrophilic and hydrophobic graphene oxide nanosheets by a solvothermal method, Carbon 2009. 47: p. 68-72
11. W. S. Hummers, R.E. Offeman, Preparation of graphitic oxide, J. Am. Chem. Soc. 1958. 80: p. 1339
12. J. Shen, Y. Hu, M. Shi, X. Lu, C. Qin, C. Li, and M. Ye, Fast and Facile Preparation of Graphene Oxide and Reduced Graphene Oxide Nanoplatelets, Chem. Mater. 2009. 21: p. 3514-3520
13. G. Chen, C. Wu, W. Weng, D. Wu, W. Yan, Preparation of polystyrene/graphite nanosheet composite, Polymer 2003. 44: p. 1781-1784
14. N.R. Wilson, P.A. Pandey, R. Beanland, R.J. Young, I.A. Kinloch, L. Gong, Z. Liu, K. Suenaga, J.P. Rourke, S.J. York, J. Sloan, Graphene Oxide: Structural Analysis and Application as a Highly Transparent Support for Electron Microscopy, ACS Nano, 2009. 3(9): p. 2547-2556
15. D. Yang, A. Velamakanni, G. Bozoklu, S. Park, M. Stoller, R.D. Piner, S. Stankovich, I. Jung, D.A. Field, C.A. Ventrice Jr., R.S. Ruoff, Chemical analysis of graphene oxide films after heat and chemical treatments by X-ray photoelectron and Micro-Raman spectroscopy, Carbon 2009. 47: p. 145-152
16. V.C. Tung, M.J. Allen, Y. Yang, Ri.B. Kaner, High-throughput solution processing of large-scale graphene, Nat. Nanotechnol., 2009. January 4: p. 25-29
17. M.K. Nazeeruddin, R. Humphry-Baker, P. Liska, M. Grätzel, Investigation of Sensitizer Adsorption and the Influence of Protons on Current and Voltage of a Dye-Sensitized Nanocrystalline TiO2 Solar Cell, J. Phys. Chem. B 2003. 107: p. 8981-8987.
18. Y.B. Tang, C.S. Lee, J. Xu, Z.T. Liu, Z.H. Chen, Z. He, Y.L. Cao, G. Yuan, H. Song, L. Chen, L. Luo, H.M. Cheng, W.J. Zhang, I. Bello, S.T. Lee, Incorporation of Graphenes in Nanostructured TiO2 Films via Molecular Grafting for Dye-Sensitized Solar Cell Application, ACS Nano 2010. 4: p. 3482-3488.
19. M. Liang, B. Luo, L. Zhi, Application of graphene and graphene-based materials in clean energy-related devices, Int. J. Energ. Res. 2009. 33: p. 1161-1170.
20. 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 2004. 306: p. 666-669.
21. X. Wang, L. Zhi, K. Müllen, Transparent, Conductive Graphene Electrodes for Dye-Sensitized Solar Cells, Nano Lett. 2008. 8: p. 323-327.
22. S. Russo, M.F. Craciun, M. Yamamoto, S. Tarucha, A.F. Morpurgo, Double-gated graphene-based devices, New J. Phys. 2009. 11: p. 095018.
23. J.S. Lee, K.H. You, C.B. Park, Highly Photoactive, Low Bandgap TiO2 Nanoparticles Wrapped by Graphene, Adv. Mater. 2012; 24: p. 1084-1088.
24. X. Pan, Y. Zhao, S. Liu, C.L. Korzeniewski, S. Wang, Z. Fan, Comparing Graphene-TiO2 Nanowire and Graphene-TiO2 Nanoparticle Composite Photocatalysts, ACS Appl. Mat. Interfaces 2012. 4: p. 3944-3950.
25. Y.H. Ng, I.V. Lightcap, K. Goodwin, M. Matsumura, P.V. Kamat, To What Extent Do Graphene Scaffolds Improve the Photovoltaic and Photocatalytic Response of TiO2 Nanostructured Films?, J. Phys. Chem. Lett. 2010. 1: p. 2222-2227.
26. N.J. Bell, Y.H. Ng, A. Du, H. Coster, S.C. Smith, R. Amal, Understanding the Enhancement in Photoelectrochemical Properties of Photocatalytically Prepared TiO2-Reduced Graphene Oxide Composite, J. Phys. Chem. C 2011. 115: p. 6004-6009.
27. S. Sun, L. Gao, Y. Liu, Enhanced dye-sensitized solar cell using graphene-TiO2 photoanode prepared by heterogeneous coagulation, Appl. Phys. Lett. 2010. 96: p. 083113.
28. T.H. Tsai, S.C. Chiou, S.M. Chen, Enhancement of Dye-Sensitized Solar Cells by using Graphene-TiO2 Composites as Photoelectrochemical Working Electrode, Int. J. Electrochem. Sci. 2011. 6: p. 3333-3343
29. T. Chen, W. Hu, J. Song, G.H. Guai, C.M. Li, Interface Functionalization of Photoelectrodes with Graphene for High Performance Dye-Sensitized Solar Cells, Adv. Funct. Mater. 2012. 22: p. 5245-5250.
30. J. Song, Z. Yin, Z. Yang, P. Amaladass, S. Wu, J. Ye, Y. Zhao, W.Q. Deng, H Zhang, XW Liu, Enhancement of Photogenerated Electron Transport in Dye-Sensitized Solar Cells with Introduction of a Reduced Graphene Oxide-TiO2 Junction, Chem. Eur. J. 2011. 17: p. 10832-10837.
31. N. Yang, J. Zhai, D. Wang, Y. Chen, L. Jiang, Two-Dimensional Graphene Bridges Enhanced Photoinduced Charge Transport in Dye-Sensitized Solar Cells, ACS Nano 2010. 4: p. 887-894.
32. X. Fang, M. Li, K. Guo, Y. Zhu, Z. Hu, X. Liu, B. Chen, X. Zhao, Improved properties of dye-sensitized solar cells by incorporation of graphene into the photoelectrodes, Electrochim. Acta 2012. 65: p. 174-178.
33. Z. He, G. Guai, J. Liu, C. Guo, Nanostructure control of graphene-composited TiO2 by a one-step solvothermal approach for high performance dye-sensitized solar cells, Nanoscale 2011. 3: p. 4613-4616.
34. Z. LAN, J.H. Wu, J.M. Lin, M.L. Huang, TiCl4 assisted formation of nano-TiO2 secondary structure in photoactive electrodes for high efficiency dye-sensitized solar cells, Sci. China Chem. 2014. 57: p. 888-894.
35. 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, 2011. 334: p. 629-634.
36. F. Gao, Y. Wang, J. Zhang, D. Shi, M. Wang, H.B. Robin, P. Wang, S.M. Zakeeruddin, M. Grätzel, A new heteroleptic ruthenium sensitizer enhances the absorptivity of mesoporous titania film for a high efficiency dye-sensitized solar cell, Chem. Commun. 2008. 23: p. 2577-2700.
37. J. Burschka, N. Pellet, S.J. Moon, H.B. Robin, P. Gao, M.K. Nazeeruddin, M Gra¨tzel, Sequential deposition as a route to high-performance perovskite-sensitized solar cells, Nature, 2013. 499: p. 316-320.
38. P. Chen, Y.W. Lo, T.L. Chou, J.M. Ting, Ultra-Thin TiO2 Layers for Enhancing the Conversion Efficiency of Flexible Dye-Sensitized Solar Cells, J. Electrochem. Soc. 2011. 158: p. H1252-H1257.
39. C.R. Ke, J.M. Ting, Anatase TiO2 beads having ultra-fast electron diffusion rates for use in low temperature flexible dye-sensitized solar cells, J. Power Sources 2012. 208: p. 316-321.
40. C.R. Ke, L.C. Chen, J.M. Ting, Photoanodes Consisting of Mesoporous Anatase TiO2 Beads with Various Sizes for High-Efficiency Flexible Dye-Sensitized Solar Cells, J. Phys. Chem. C. 2012. 116: p. 2600-2607.
41. L.C. Chen, J.M. Ting, Y.L. Lee, M.H. Hon, A binder-free process for making all-plastic substrate flexible dye-sensitized solar cells having a gel electrolyte, J. Mater. Chem. 2012. 22: p. 5596-5601.
42. L.C. Chen, C.R. Ke, J.M. Ting, All-Plastic Flexible Dye-Sensitized Solar Cell Based on Solution Synthesized Mesoporous Anatase TiO2 Beads, J. Electrochem. Soc. 2014. 161: p. E28-E33.
43. C.W. Hsu, P. Chen, J.M. Ting, Microwave-Assisted Hydrothermal Synthesis of TiO2 Mesoporous Beads Having C and/or N Doping for Use in High Efficiency All-Plastic FDSCs, J. Electrochem. Soc. 2013. 160: p. H160-H165.
44. H.G. Yun, Y. Jun, J. Kim, B.S. Bae, M.G. Kang, Effect of increased surface area of stainless steel substrates on the efficiency of dye-sensitized solar cells, Appl. Phys. Lett. 2008. 93: p. 133311.
45. F.Y. Ouyang, W.L. Tai, Enhanced corrosion resistance of TiN-coated stainless steels for the application in flexible dye-sensitized solar cells, Appl. Surf. Sci. 2013. 276: p. 563- 570.
46. M.G. Kang, N.G. Park, K.S. Ryu, S.H. Changa, K.J. Kim, A 4.2% efficient flexible dye-sensitized TiO2 solar cells using stainless steel substrate. Sol. Energy Mater, Sol. Cells 2006. 90: p. 574-581.
47. K. Fan, T. Peng, B. Chai, J. Chen, K. Dai, Fabrication photoelectrochemical properties of TiO2 films on Ti substrate for flexible dye-sensitized solar cells. Electrochim, Acta 2010. 55: p. 5239-5244.
48. H.G. Yun, B.S. Bae, M.G. Kang, A Simple Highly Efficient Method for Surface Treatment of Ti Substrates for Use in Dye-Sensitized Solar Cells, Adv. Energy Mater. 2011, 1: p. 337-342.
49. C.H. Lee, W.H. Chiu, K.M. Lee, W.F. Hsieh, J.M. Wu, Improved performance of flexible dye-sensitized solar cells by introducing an interfacial layer on Ti substrates, J. Mater. Chem. 2011, 21: p. 5114-5119.
50. S. Satapathi, H.S. Gill, S. Das, L. Li, L. Samuelson, M.J. Green, J. Kumar, Performance enhancement of dye-sensitized solar cells by incorporating graphene sheets of various sizes, Appl. Surf. Sci. 2014, 314: p. 638-641
51. L. Qiu, H. Zhang, W. Wang, Y. Chen, R. Wang, Effects of hydrazine hydrate treatment on the performance of reducedgraphene oxide film as counter electrode in dye-sensitized solar cells, Appl. Surf. Sci. 2014. 319: p. 339-343
52. S. Ito, N.C. Ha, G. Rothenberger, P. Liska, P. Comte, S.M. Zakeeruddin, P. Péchy, M.K. Nazeeruddin, M. Grätzel, High-efficiency (7.2%) flexible dye-sensitized solar cells with Ti-metal substrate for nanocrystalline-TiO2 photoanode, Chem. Commun. 2006. 28: p. 4004-4006.
53. J. Wu, Y. Xiao, Q. Tang, G. Yue, J. Lin, M. Huang, Y. Huang, L. Fan, Z. Lan, S. Yin, T. Sato, A Large-Area Light-Weight Dye-Sensitized Solar Cell based on All Titanium Substrates with an Efficiency of 6.69% Outdoors, Adv. Mater. 2012. 24: p. 1884-1888.
54. T.T. Wu, J.M. Ting, Bridging TiO2 nanoparticles using graphene for use in dye-sensitized solar cells, Int. J. Energy Res. 2014. 38: p. 1438-1445.
55. M. Wojtoniszak, B. Zielinska, X. Chen, R. J. Kalenczuk, E. Palen, Synthesis and photocatalytic performance of TiO2nanospheres-graphene nanocomposite under visible and UV light irradiation, J. Mater. Sci. 2012. 47: p. 3185-3190.
56. R.M. Mohamed, UV-assisted photocatalytic synthesis of TiO2-reducedgraphene oxide with enhanced photocatalytic activity in decomposition of sarin in gas phase. Desalin, Water treat. 2012. 50: p. 147-156.
57. S.R. Kim, M. K. Parvez, M. Chhowalla, UV-reduction of graphene oxide and its application as an interfacial layer to reduce the back-transport reactions in dye-sensitized solar cells, Chem. Phys. Lett. 2009. 483: p. 124-127.
58. T.T. Wu, J.M. Ting, Preparation characteristics of graphene oxide its thin films, Surf. Coat. Technol. 2012. 231: p. 487-491.
59. Hara, Kohjiro and Arakawa, Hironori (2005). “Chapter 15. Dye-Sensitized Solar Cells”. In A. Luque and S. Hegedus. Handbook of Photovoltaic Science and Engineering (PDF). John Wiley & Sons.
60. Y. J. Kim, M. H. Lee, H. J. Kim, G. Lim, Y. S. Choi, N. G. Park, K. Kim and W. I. Lee, Formation of Highly Efficient Dye-Sensitized Solar Cells by Hierarchical Pore Generation with Nanoporous TiO2 Spheres, Advanced Materials, 2009. 21 (36): p. 3668-3673.
61. J.E. Hu, S.Y. Yang, J.C. Chou, P.H. Shih, Fabrication of flexible dye-sensitised solar cells with titanium dioxide thin films based on screen-printing technique. Micro Nano Lett. 2012. 7: p. 1162-1165.
62. S. Ito, T.N. Murakami, P. Comte, P. Liska, C. Grätzel, M.K. Nazeeruddin, M. Grätzel, Fabrication of thin film dye sensitized solar cells with solar to electric power conversion efficiency over 10%, Thin Solid Films, 2008. 516: p. 4613-4619.
63. W.Y. Wu, T.W. Shih, P. Chen, J.M. Ting, J.M. Chen. Plasma Surface Treatments of TiO2 Photoelectrodes for Use in Dye-Sensitized Solar Cells, J. Electrochem. Soc. 2011. 158: p. K101-K106.
64. S. Duquesnéńy, M.L. Bras, S. Bourbigot, R. Delobel, H. Vezin, G. Camino, B. Eling, C. Lindsay, T. Roels, Expandable graphite: a fire retardant additive for polyurethane coatings, Fire Mater. 2003. 27: p. 103-117
65. H. Hiura, T.W. Ebbesen, K. Tanigaki, Raman studies of carbon nonotubes, Chem. Phys. Lett. 1993. 202: p. 509-512.
66. J. Robertson, Diamond-like amorphous carbon, Mater. Sci. Eng. R-Rep. 2002. 37: p. 129-281
67. S.D. Gardner, C.S.K. Singamsetty, G.L. Booth, G.R. He, JR., Surface Characterization of carbon fibers using angle-resolved XPS and ISS, Carbon, 1995. 33(5): p. 587-595
68. D.S. Campbell, H.J. Leary, J.S. Slattery, JR. , R.J. Sargent, IBM General Technology Division, Essex Junction, VT 05452, p. 328-329
69. S. Delpeux, F. Beguin, I. Rashkov, N. Manolova, R. Benoit, R. Erre, Fullerene core star-like polymers-1. Preparation from fullerenes and monoazidopolyethers, Eur. Polym. J. 1998. 34(7): p. 905-915
70. G.I. Titelman, V. Gelman, S. Bron. Characteristics and microstructure of aqueous colloidal dispersions of graphite oxide, Carbon 2005. 43: p. 641-649.
71. N.R. Wilson, P.A. Pandey, R. Beanland, R.J. Young, I.A. Kinloch, L. Gong, Z. Liu, K. Suenaga, J.P. Rourke, S.J. York, J. Sloan. Graphene Oxide: Structural Analysis and Application as a Highly Transparent Support for Electron Microscopy, ACS Nano 2009. 3: p. 2547-2556.
72. W.Y. Wu, T.W. Shih, J.M. Ting. Hydrothermally synthesized TiO2 nanopowders and their use as photoanodes in dye-sensitized solar cells, Int. J. Energ. Res. 2013. 37: p. 964-972.
73. P. Mérel, M. Tabbal, M. Chaker, S. Mois, J. Margot, Direct evaluation of the sp3 content in diamond-like-carbon films by XPS, Appl. Surf. Sci. 1998. 136: p. 105-110.
74. M.C. Hsiao, S.H. Liao, M.Y. Yen, C.C. Teng, S.H. Lee, N.W. Pu, C.A. Wang, Y. Sung, M.D. Ger, C.C.M. Ma, M.H. Hsiao. Preparation and properties of a graphene reinforced nanocomposite conducting plate, J. Mater. Chem. 2010. 20: p. 8496-8505.
75. J.I. Paredes, S. Villar-Rodil, P. Solís-Fernández, A. Martínez-Alonso, J.M.D. Tascón. Atomic Force and Scanning Tunneling Microscopy Imaging of Graphene Nanosheets Derived from Graphite Oxide, Langmuir 2009. 25: p. 5957-5968.
76. Z.S. Wang, H. Kawauchi, T. Kashima, H. Arakawa, Significant influence of TiO2 photoelectrode morphology on the energy conversion efficiency of N719 dye-sensitized solar cell, Coord. Chem. Rev. 2004. 248: p. 1381-1389.
77. J.V.D. Lagemaat, A.J. Frank, Nonthermalized Electron Transport in Dye-Sensitized Nanocrystalline TiO2 Films:  Transient Photocurrent and Random-Walk Modeling Studies, J. Phys. Chem. B 2001. 105: p. 11194-11205
78. A.J. Frank, N. Kopidakis, J. Lagemaat, Electrons in nanostructured TiO2 solar cells: transport, recombination and photovoltaic properties, Coord. Chem. Rev. 2004. 248: p. 1165-1179.
79. L. Dloczik, O. Iluperama, I. Lauermann, L.M. Peter, E.A. Ponomarev, G. Redmond, N.J. Shaw, I. Uhlendorf, Dynamic Response of Dye-Sensitized Nanocrystalline Solar Cells: Characterization by Intensity-Modulated Photocurrent Spectroscopy, J. Phys. Chem. B 1997. 101: p. 10281-10289.
80. N. Kopidakis, E.A. Schiff, N.G. Park, J.V.D. Lagemaat, A.J. Frank, Ambipolar Diffusion of Photocarriers in Electrolyte-Filled, Nanoporous TiO2, J. Phys. Chem. B 2000. 104: p. 3930-3936.
81. N.G. Park, J.V.D. Lagemaat, A.J. Frank, Comparison of Dye-Sensitized Rutile- and Anatase-Based TiO2 Solar Cells, J. Phys. Chem. B 2000. 104: p. 8989-8994.
82. M. Toivola, J. Halme, K. Miettunen, K. Aitola, P.D. Lund, Nanostructured dye solar cells on flexible substrates - Review, Int. J. Energ. Res. 2009. 33: p. 1145-1160.
83. S.K. Mohapatra, M. Misra, V.K. Mahajan, K.S. Raja, Design of a Highly Efficient Photoelectrolytic Cell for Hydrogen Generation by Water Splitting: Application of TiO2-xCx Nanotubes as a Photoanode Pt/TiO2 Nanotubes as a Cathode, J. Phys. Chem. C. 2007. 111: p. 8677-8685.