本研究目的在增進染料敏化太陽能電池於室內光照條件下之光電轉換效率。選用具有較正氧化還原電位、低競爭吸光之鈷氧化還原對做為電解質系統，結合高消光係數之MK-2染料作為光敏化劑，並藉由工作電極的前、後處理，以及膠態電解質中奈米粒子的添加來改善元件轉換效率。首先利用乙氰(AN)溶劑製備而成的液態電解質來探討工作電極前、後處理對元件效能之影響。研究結果顯示，在網印二氧化鈦薄膜前先以噴霧熱解法對FTO導電玻璃進行前處理，形成一層緻密的TiO2阻擋層，可以有效抑制鈷氧化還原對和導電玻璃上之電子發生再結合反應，提升元件短路電流、開路電壓與填充因子，元件輸出功率在200-lux光強之T5燈管照射下可提升至9.44 µW/cm2。若將網印後的二氧化鈦薄膜再利用四氯化鈦溶液(TiCl4,aq)浸泡後處理後，可以進一步改善電子於二氧化鈦薄膜的傳輸，提升元件之電子收集率及短路電流大幅上升，因此元件輸出功率可再提升至11.56 µW/cm2。本研究亦比較不同電解質溶劑對元件效能之影響，結果顯示選用穩定性較高且不會發生染料脫附之3-甲氧基丙腈 (3-Methoxypropionitrile, MPN)溶劑所製備而成的元件，元件輸出功率又進一步提升至12.44 µW/cm2。接著添加膠化劑—聚偏二氟乙烯-三氯乙烯(Poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP)以及4wt% ZnO奈米粒子於MPN鈷液態電解質中製備出膠態電解質，能夠使元件開路電壓大幅提升，輸出功率高達13.12 µW/cm2。將上述液態、膠態，與添加4wt% ZnO奈米粒子之膠態三種元件置於室溫以及室內光200-lux下持續照光1000小時後，三者元件皆可維持將近100%之初始效率。

The purpose of this study is to improve the conversion efficiency of dye-sensitized solar cells (DSSCs) under indoor lighting condition. DSSCs based on the cobalt redox couples and commercial MK-2 dye are fabricated, and several strategies are adopted to improve the photovoltaic performance. The results show that the compact layer deposited onto FTO substrates plays a crucial role in inhibiting the charge recombination between the FTO and cobalt redox couples. When acetonitrile (AN) is used as the solvent of the liquid electrolyte, the DSSC containing a thick blocking layer prepared by spray pyrolysis shows an output power of 9.44 µW/cm2 under 200-lux illumination of T5 light. Furthermore, the electron transport in the TiO2 matrices can be enhanced by using the TiO2 films with TiCl4 post-treatment, leading to a higher output power of 11.56 µW/cm2. The effect of different electrolyte solvent is also compared. The results show that the output power can achieve 12.44 µW/cm2 when the 3-methoxypropionitrile (MPN) solvent is utilized. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ZnO nanoparticles were utilized as the gelator and nano-fillers, respectively, to prepare the gel electrolyte. The results show that the presence of ZnO nanoparticles can significantly increase the output power to a value of 13.12 µW/cm2, which is ascribed to ZnO effects on the change of TiO2 conduction band level, as well as the inhibition of charge recombination at the TiO2/electrolyte interface. Finally, the stability tests show that the output power of liquid and gel-state cells can maintain 100% of their initial values after 1000 hours of 200-lux illumination.

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