為了提升染料敏化太陽能電池光電轉換效率與降低製程複雜度及成本，本研究新開發出利用兩段式水熱法成長珊瑚狀二氧化鈦奈米線與珊瑚狀樹枝奈米線結構，以增加表面積粗糙度及染料吸附量。以及利用RF Sputter濺鍍高品質緻密性的二氧化鈦薄膜，改善TCO/TiO2介面所造成的暗電流。
經利用濺鍍機製備二氧化鈦緻密層(compact layer)改善TCO/TiO2介面所造成的電子複合，減少了暗電流亦即電子反向流動的發生，以抑制TiO2上的電子回傳給氧化態電解質而產生interception的作用。本研究所製備的二氧化鈦緻密層，可當作利用水熱法成長一維，單晶二氧化鈦奈米線之晶種層(seed layer)。
至於珊瑚狀奈米線(coral-like NWs)和珊瑚狀樹枝奈米線(coral-like nanobranch)結構方面，藉由提高表面粗糙度及染料吸附量以及一維結構之量子侷限效應，以提升光電轉換效率。經實驗得知，當水熱法成長二氧化鈦珊瑚狀奈米線與珊瑚狀樹枝奈米線的成長時間為8 h時，可得較佳之光電轉換效率(η)分別為2.43 %與5.46 %。本研究所提出的結構，明顯有效的提高表面粗糙度及染料吸附量，進一步改善染料敏化太陽能電池光電特性。
本研究以濺鍍機製備二氧化鈦緻密層，搭配HTG製備出具有良好的單晶、高表面積、可吸附較多的光敏染料、製程簡便、成本低的珊瑚狀奈米線和珊瑚狀樹枝奈米線結構。預期在未來染料敏化太陽能電池元件應用上極具潛力。

Enhancing the efficiency of Dye-Sensitized Solar Cell (DSSC) using novel photoanode structures and improving charge recombination at the TCO/TiO2 interface of the proposed photoanodes have been demonstrated in this work.
A sputtering-deposited compact TiO2 layer was employed to reduce the charge recombination at the TCO/TiO2 interface and suppress the inverse dark-current, thus decreasing the interception of electrons into oxidized electrolyte in TiO2 layer. In addition, the compact TiO2 layer was also served as a seed layer for the growth of TiO2 nanowire by hydrothermal growth (HTG) method.
Two types of photoanode with novel nano-structures (i.e., coral-like TiO2 nanowires and nanobranchs using a two-step HTG processes) were proposed to promote photovoltaic performance of DSSCs in our experiments. It is found that DSSCs with coral-like TiO2 and coral-like TiO2 nanobranchs prepared by HTG for 8 hr would have the best photovoltaic performance with a conversion efficiency (η) 2.43 % and 5.46 %, respectively. Such improvements should be due to the proposed photoanodes providing a considerable increase in surface roughness and absorption efficiency of dye molecules.
It is expected that the photoanodes proposed in the present study would have promising potentials for the realization of high efficient DSSCs.

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