本研究採用溶膠凝膠法搭配微波溶熱法快速合成奈米銳鈦礦相二氧化鈦膠體溶液，反應後之產物無需經過溶劑的置換，且僅需經由適當機械震盪即可有效分散膠體粒子，可用來直接製備DSSC工作電極網印所需之漿料，有效改善傳統漿料製備耗時的缺點。在膠體溶液的分散處理方面，以超音波震盪搭配超音波細胞粉碎機可以達到最佳且單一粒徑分佈的分散效果，分散效果接近單晶粒子大小。而在漿料的配方部分，研究結果發現當二氧化鈦膠體粒子的分散情形接近晶粒大小時，製成的厚膜會因晶粒間孔隙過小，在燒結處理後會有膜裂的現象發生，而在漿料中添加微量去離子水，可使晶粒發生輕微的凝聚作用，反而有助於改善膜裂的情形。此外，在溶膠凝膠法搭配微波溶熱反應過程中，透過改變反應溶劑及螯合劑的添加，可合成不同晶粒大小及不同發展晶面的二氧化鈦奈米晶粒。結果發現，以辛醇作為溶劑所合成的二氧化鈦晶粒具有最高比表面積，其染料吸附率最高，在相同工作電極厚度下，具有最高的光電轉換效率，透過散射層添加電池轉換效率可高達7.70 %。在二氧化鈦晶粒的發展晶面影響上，{001}晶面具有較佳的電子壽命，可抑制DSSC中的電子電洞再結合反應，在相同晶粒尺寸的條件下，可產生較高的光電轉換效率。

A clean and time-effective process to prepare anatase TiO2 colloidal solution via sol-gel microwave-assisted solvothermal method and its application for dye-sensitized solar cells was investigated in this study. Via a sol-gel microwave-assisted solvothermal reaction, the as-prepared colloidal solutions can be directly used for the paste preparing without the need of solvent exchange. Simple bath and probe sonication treatments allow to improve the aggregation of anatase nanoparticles and is beneficial for obtaining homogeneous TiO2 paste. However, the well-dispersed TiO2 films were found to induce cracks as removing the solvent and binders due to the small pore size of films. In this case, addition of a small amount of deionic water into the paste provoked a slight aggregation of TiO2 nanoparticles and effectively avoided the occurrence of film cracks. In parallel, anatase nanocrystals exposed of {001} or {101} facets were tailored by using different solvents or chelating agent in sol-gel processes. Anatase nanocrystallites exposed of {001} facets were found to retard the electron recombination and increase electron lifetime in DSSC. TiO2 prepared using 1-octanol exhibited small crystallite size around 4-8 nm but also the longest electron transportation path. The photoanode prepared using OCT sample demonstrated the optimal dye loading properties and longest electron lifetime that demonstrates a power conversion efficiency up to 7.7 %.

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