本研究以全溶液法成長氧化鋅奈米線/片狀複合結構，首先利用化學浴沉積法(chemical bath deposition，CBD)，於ITO玻璃基板上成長氧化鋅奈米線陣列，再利用室溫化學浴法，於已成長之奈米線陣列外成長片狀結構，形成一同時具有良好電子傳輸特性與高表面積之複合薄膜。根據高解析穿透式電子顯微鏡之分析，顯示此複合結構之奈米線主幹與片狀結構皆為單晶結構。以此複合結構為染料敏化電池之光陽極，可大幅提升奈米線陣列之光電轉換效率，於膜厚約9微米時可達5.14%，且經由光強度調制光電流分析儀(intensity modulated photocurrent spectroscopy，IMPS)分析顯示經室溫化學浴後的產物，相對於奈米線陣列具有良好之電子傳輸性質。本研究亦針對此製程之進行改良，使全製程溫度低於120 oC以應用於可撓式元件。此全低溫製程應用於以ITO玻璃基板，當膜厚約3微米時，元件光電轉換效率可達3.07%，而目前尚未針對製程進行最佳化，因此以ITO-PET為基板轉換效率僅接近1%。

Zinc oxide nanowire/nanosheet hierarchical structure have been successfully synthesized by a wet-chemical route. At first, ZnO nanowire array is synthesized by chemical bath deposition (CBD) on ITO glass substrates. Then, an outer shell composed of many nanosheets structure is grown by another room-temperature CBD on the as-prepared nanowire surface, which becomes a high surface area composite with an excellent electron transport characteristic. High-resolution transmition electron microscopy (HR-TEM) characterizations reveal that the nanowire and nanosheet both are single crystalline with some specific relations between each other. Compared to bare nanowire array, a remarkable increase of the photon to electron efficiency is achieved by using this hierarchical ZnO structure as the photoanode of the dye-sensitized solar cell (DSSC). Using the hierarchical ZnO structure as the photoanode, the DSSC attains a photon to electron efficiency of 5.14% with a composite film thickness of 9 μm. The results of the intensity modulated photocurrent spectroscopy (IMPS) reveal that the hierarchical structures grown by room-temperature CBD possess an excellent electron transport property compared to the as-prepared nanowire. Finally, a wet-chemical route with temperatures below 120 oC is further developed in this study for flexible DSSCs. A photon to electron efficiency of 3.07% is attained by using the low-temperature grown ZnO nanostructure with 3-μm film thickness on ITO glass. So far, the efficiency was below 1% on ITO-PET because of the lack of process optimization.

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