二次陽極氧化法之TiO2奈米管陣列薄膜在染料敏化太陽能電池上應用

本論文研究二次陽極氧化法製備TiO2奈米管陣列薄膜與離子液體，藉由提供電子快速傳輸通道，有助於提升電池元件的效能，同時改善液態電解質容易揮發的問題。研究部分主要分為﹕1.製備有序列的奈米管陣列，給電子一傳輸通道，降低電子-電洞再結合；2.電解液製備與改良，提升元件的光電轉換效率。在光電極部分，本研究探討使用二次陽極氧化法來減少反應時間。實驗中提升電化學陽極氧化的溫度，來加快反應速率，降低實驗所需時間，並製備不同陽極氧化時間的奈米管陣列，以XRD分析其晶相，以SEM分析表面型態，分析其管長、管徑與管壁，最後將其進行二氧化鈦光電極結構設計，製備出具高效率的染料敏化太陽能電池。實驗結果表示以奈米粒子（NP）為黏著劑，將奈米管陣列薄膜轉印其上的光電極，其染料敏化太陽能電池元件轉換效率為4.24%。在電解液部分，本研究用傳統液態電解液、自製離子液體BmimI取代傳統電解液中的碘化鋰（LiI），來探討其與電池效率之關係。研究的結果顯示，奈米鈦管陣列薄膜唯一維方向性結構，離子液體在其表面形成高度排列的結構，此種具方向性的離子傳導通道，可提升離子的擴散與移動性。研究結果表示使用離子液體取代傳統電解液中碘化鋰（LiI），電池元件可達到最好的性能，若以奈米粒子為底層，奈米管陣列薄膜為上層的染料敏化太陽能電池元件的光伏性能達到最佳，提升其41%的效能。

關鍵字

二次陽極氧化法；奈米粒子；二氧化鈦奈米管陣列；二氧化鈦光電極；離子液體

並列摘要

The aim of this thesis studies TiO2 nanotube array film prepared by the second-step anodic treatment of Ti foil in ethylene glycol(C2H6O2) with the addition of 0.5 wt% NH4F and 0.2 wt% H2O. This film can provide high speed transportable channel for electronic, which increase the dye-sensitized solar cell (DSSC) performance and stability by using ionic liquid as electrolyte. The study includes: 1. Preparation of TiO2 nanotube array provides electron transportable channel to reduce the electron-hole recombination. 2. Preparation and improvement of liquid electrolyte enhance the photoelectric conversion efficiency and stability of the DSSC. In photoelectrode part, we used the second-step anodic treatment of Ti foil to prepare TiO2 nanotube array for decreasing reaction time. Increasing anodic treatment temperature accelerates reaction rate and decreases the reaction time. We also prepared TiO2 nanotube array at different anodic treatment time to analyze crystal phase by XRD, surface morphology and nanotube structure by SEM. At last we designed the TiO2 photoelectrode configuration and prepared DSSC with high efficiency. The results show that the conversion efficiency of DSSC is about 4.24 % by using the dye-loaded TiO2 nanotube array as photoelectrode. In electrolyte part, we utilized the ionic liquid BmimI to replace LiI in the traditional electrolyte and discuss the relationship between cell efficiency and electrolyte. The results that TiO2 nanotube array film is a one-dimension structure which make ionic liquid self-assembling highly ordered on TiO2 nanotube array surface. This ionic transportable channel increases ionic diffusion and mobility. The photovoltaic performance of DSSC can increase 41 % efficiency by using TiO2 photoelectrode with nanoparticle as bottom layer and nanotube array film as top layer.

並列關鍵字

Second-step anodic treatment ； Nanoparticle ； TiO2 nanotube array ； TiO2 photoelectrode ； ionic liquid

參考文獻

[1] M Grätzel and B.O Regan, “ A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films ”, Nature 353, pp.737-740, 1991.

Google Scholar

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