在此研究中，我們製備了山丘形多層級的二氧化鈦薄膜，吸附染料後做為染料敏化太陽能電池(DSSC)的光電極層，預期在此結構當中，適度聚集的二氧化鈦顆粒(~21nm)團聚物能增強光散射達到良好的光捕捉，同時擁有較高的比表面積以利染料吸附，進而增加染料敏化太陽能電池的光電轉換效率。為了對薄膜的光學性質進行詳細探討以及元件最佳化的需求，我們使用不同分子量的聚乙烯醇(PVA)於二氧化鈦漿料當中，達到不同聚集程度的二氧化鈦微粒。成膜後，將這些擁有不同表面結構型態的二氧化鈦薄膜進行光電性質的量測，包括光反射率、光吸收、染料吸附量以及組成元件後的特性測定。其中一組最佳元件同時擁有高染料吸附量以及良好的光散射，與傳統未加PVA的元件相比，其攸關太陽能電池效率的短路電流(Jsc)增加了23%左右。此外，我們發現電解液在此具有更高多孔性結構當中的滲透性較傳統薄膜良好。以液態電解液與膠態電解液組裝元件來比較短路電流，經過PVA處理的薄膜比傳統薄膜分別提升16%與19%，其中膠態電解液多出的成長是因為在此高黏度的電解液系統中，山丘形多層級結構比均勻堆積結構擁有更良好的電解液穿透性，優化元件效率。

In this research, hills-like hierarchical structured TiO2 photoanodes for dye-sensitized solar cells (DSSCs) have been prepared. We expected these appropriately aggregated TiO2 clusters in photoanode layer could cause stronger light scattering and higher dye loading that increased efficiency of photovoltaics. For detailed light-harvesting study, different molecular weight of polyvinyl alcohol (PVA) polymers were used as binders for TiO2 nanoparticles (P-25 Degussa) aggregation. After preparing a series of TiO2 films with dissimilar morphology, the reflection of TiO2 films, absorbance of attached dye, amount of dye loading, and performance of fabricated DSSC devices were measured and investigated. An optimized device had higher dye loading and well light harvesting at the same time that induced a 23% increase of short-circuit current Jsc in DSSCs. Moreover, we found that electrolyte could penetrate or diffuse easily in this higher porous structure. We fabricated dye-sensitized solar cells with MPN-based liquid electrolyte and gel polymer electrolyte. From this structure, the short-circuit current Jsc was increased around 16% and 19% respectively compared to conventional layers with liquid electrolyte and gel polymer electrolyte devices. The increase in highly viscous system of gel polymer electrolyte is due to easier penetration by such hills-like hierarchical structure.

目錄
摘要 ............................................................................................................... i
Abstract ........................................................................................................ ii
目錄 ............................................................................................................. iii
圖目錄 ........................................................................................................ vii
表目錄 .......................................................................................................... x
第一章緒論 ................................................................................................1
1.1 前言 .................................................................................................1
1.2 研究動機 .........................................................................................2
第二章染料敏化太陽能電池與文獻回顧 ................................................4
2.1 無機太陽能電池 .............................................................................4
2.2 有機太陽能電池 ............................................................................5
2.3 染料敏化太陽能電池結構與原理 .................................................7
2.3.1 染料敏化太陽能電池 ...........................................................7
2.3.2 透明導電基板(TCO substrate) .............................................9
2.3.3 緻密層(Dense layer) .............................................................9
2.3.4 二氧化鈦電極 ......................................................................9
2.3.5 染料 ................................................................................... 12
2.3.6 電解液 ............................................................................... 17
2.3.7 對電極(鉑電極) ................................................................. 18
2.4 染料敏化太陽能電池之工作原理 ............................................. 19
2.4.1 工作原理 ........................................................................... 19
2.4.2 電子電洞對分離 ............................................................... 21
2.5 散射(scattering) ........................................................................... 23
第三章實驗器材及藥品 ......................................................................... 25
3.1 紫外與可見光光譜儀(UV-Vis Spectrometer) .............................. 25
3.2 場發射型掃描式電子顯微鏡FEG-SEM(Field Emission
Gun-scanning Electron Microscopy) .................................................. 26
3.3 旋轉塗佈機(Spin Coater) ............................................................ 27
3.4 高溫爐 ......................................................................................... 28
3.5 太陽光譜模擬量測系統(Solar Simulator System) ..................... 29
3.5.1 性能參數 ........................................................................... 30
3.5.1.1 短路電流Jsc .................................................................... 30
3.5.1.2 開路電壓Voc .................................................................. 31
3.5.1.3 填充因子FF ................................................................... 31
3.5.1.4 電池總效率η .................................................................. 32
3.6 分光效率量測儀 .......................................................................... 33
3.7 交流阻抗分析儀(AC-Impedance) ............................................... 34
3.8 實驗藥品 ...................................................................................... 38
第四章實驗步驟 ..................................................................................... 41
4.1 DSSC 元件製作流程 ................................................................ 41
4.1.1 流程圖 ............................................................................... 41
4.1.2 ITO 基板的清潔流程 ......................................................... 42
4.1.3 配製TiO2 緻密層溶液 ...................................................... 42
4.1.4 配製TiO2 漿料 .................................................................. 43
4.1.5 以旋轉塗佈機成膜(Spin Coating) .................................... 44
4.1.6 高溫鍛燒 ........................................................................... 48
4.1.7 染料配製與DSSC 元件組裝 ............................................. 48
4.2 染料吸附量的測定 ..................................................................... 53
第五章實驗結果與討論 ......................................................................... 56
5.1 二氧化鈦薄膜表面型態(Morphology) ....................................... 56
5.1.1 經過PVA 處理過的TiO2 聚集物 ..................................... 56
5.1.2 多層級結構之二氧化鈦薄膜 ............................................ 60
5.2 二氧化鈦光電極薄膜的光學性質 ............................................. 62
5.2.1 二氧化鈦薄膜的光反射率 ................................................ 62
5.2.2 二氧化鈦薄膜的光散射 ................................................... 65
5.3 光散射對染料敏化太陽能電池的效率增益 .............................. 70
5.4 多層級結構對電解質擴散的影響 ............................................. 73
總結 ........................................................................................................... 77

1. B. O’Regan, M. Grätzel, Nature 353, 737 (1991)
2. M. Grätzel, Journal of Photochemistry and Photobiology A: Chemistry 164, 3 (2004)
3. Z. Wang, H. Kawauchi, T.Kashima, H. Arakawa, Coord. Chem Rev. 248, 1381 (2004)
4. J. Ferber and J. Luther, Sol. Energ. Mat. Sol. Cells 54, 265 (1998)
5. M. Grätzel, Acc. Chem. Res.42, 1788 (2009)
6. Henry J. Snaith, Adv. Funct. Mater. 20, 13 (2010)
7. Martin A. Green1, Prog. Photovolt:Res. Appl. 16, 61 (2008)
8. A. Fujishima and K. Honda, Nature 238, 37 (1972)
9. H. Gerischer, J. Goberecht, Ber. Bunsenges. Phys. Chem. 80, 327 (1976)
10. H. Tributsch, H. Gerischer, Ber. Bunsenges. Phys. Chem. 73, 251 (1969)
11. A. Fujishima, T. Iwase, T. Watanabe, and K. Honda, J. Am. Chem. Soc. 97, 4134 (1975)
12. M. Matsumura, Y. Nomura, and Hiroshi Tsubomura, Bull. Chem. Soc. Jpn. 49, 1409 (1976)
13. G. Sivalingam, Applied Catalysis B: Environmental 45, 23 (2003)
14. N.-G. Park, J. van de Lagemaat, and A. J. Frank, J. Phys. Chem. B 104, 8989 (2000)
15. J. Bisquert, J. Phys. Chem. B 106, 325 (2002)
16. G. J. Meyer, J. Chem. Educ. 74, 652 (1997)
17. Hara, Langmuir 20, 4205 (2004)
18. Hara, Sol. Energ. Mat. Sol. Cells 77, 89 (2003)
19. Klein, Inorg. Chem. 44, 178 (2005)
20. M. Grätzel, Inorg. Chem. 44, 6841 (2005)
21. Wang, J.Am. Chem. Soc. 127, 808 (2005)
22. M. Grätzel, Acc. Chem. Res. 33, 269 (2000)
23. J. H. Yum, P. Chen, M. Grätzel, Mohammad K. Nazeeruddin, Chem. Sus. Chem. 1, 699 (2008)
24. A. Zaban, S. Ferrere, B. A. Gregg, J. Phys. Chem. B 102, 452 (1998)
25. 網站：http://en.wikipedia.org/wiki/Diffuse_reflection
26. L. Han, N. Koide, Y. Chiba, and T. Mitate, Appl. Phys. Lett., 84, 2433 (2004)