- 學位論文
氧化鋅奈米線光陽極之半固態染料敏化太陽能電池製作
ZnO Nanowires as Photoanode Material for Quasi-Solid State Dye-Sensitized Solar Cells
摘要
近幾年來，染料敏化太陽能電池 (dye-sensitized solar cells, DSCs) 由於更低的製造成本，並且有運用於可撓性基板的潛力引起了許多的注意以及研究。本實驗利用高溫熱蒸鍍法合成高品質的氧化鋅奈米線並應用於光陽極中，具備了良好電子傳遞能力，由於單純氧化鋅奈米線表面積過小，不利於大量染料吸附更，故利用額外加入氧化鋅奈米線提供分支成長的主幹，再經過二次成長的方式增加表面積達到提高染料吸附量的目的，也增強了光散射效果，將短路電流由單純奈米線光陽極的4.07 mA/cm2提升至分支狀結構光陽極的5.38 mA/cm2，轉換效率跟填充因子分別達到1.57 % 與0.50。另外，一般DSCs使用液態電解液，但電解液洩漏以及揮發的問題嚴重考驗封裝技術，目前也有許多研究投入於固態如有機或無機電洞傳遞材料、聚合物電解液，或半固態如膠態聚合物電解液等方式取代液態電解液。由於膠態電解液具備良好導電率，以及對光陽極更佳的介面接觸和良好的填洞能力，故本實驗使用膠態電解液 (gel electrolyte)組成半固態的DSCs，藉此防止電解液洩漏以及提高電池的穩定度，在效率及填充因子得到0.70 % 和0.54的結果，較低的短路電流以及轉換效率是由於相對液態電解液更低的離子擴散速率，不過半固態染料敏化太陽能電池有著更高的開路電壓。穩定度測試仍不盡理想，若能改善封裝技術則能更進一步改進電池穩定度。
並列摘要
In recent years, much attention has been paid to the development of dye-sensitized solar cells (DSCs) because of their low production cost. In this study, the growth of well-aligned single-crystalline ZnO nanowires (NWs) is realized on bare transparent conductive oxide (TCO) glass substrates by thermal evaporation. Although the NWs provide a good electron transport path, the surface area of the NWs is too small for dye loading. In this study, additional ZnO NWs for backbones of branched NWs were added and a secondary growth was introduced to raise the surface area of the photoanode and enhance the light scattering effect. The Short-circuit current density(JSC) was improved to 5.38 mA/cm2 for the branched NW photoanode from 4.07 mA/cm2 for the bare NW photoanode. The highest conversion efficiency and the fill factor were around 1.57% and 0.50, respectively. On the other hand, liquid electrolytes are usually used in DSCs, rendering leakage and evaporation problems. To solve these problems, solid-state hole transporters, whether organic or inorganic, polymer electrolytes and gel polymer electrolytes have been used to replace liquid electrolytes in many reports. A gel electrolyte with good contact, reasonable conductivity, ease of fabrication, was prepared to make quasi-solid state DSCs. The highest efficiency of 0.7% and the fill factor of 0.54 have been achieved. In comparison with DSCs with liquid electrolytes, the relative low JSC and the efficiency are due to the lower ion diffusion velocity.