以電氣紡絲及電泳沉積法改善染料敏化太陽能電池可撓性之研究

Abstract

染料敏化太陽能電池為新一代太陽能電池，由於不需昂貴真空設備，製程相較其他種類太陽能電池簡單且材料成本在大面積製作後可以降低，成為近20年研究機構甚至產業界極為重視的課題。為了創造更生活化的應用。例如把太陽電池變成可捲起來帶著走的行動電力，或可供人穿戴的太陽電池衣或背包。目前可撓式DSSC在製程上雖然還有許多待改進的問題，但是為未來研究的重點。 本研究利用電氣紡絲法與電泳沉積法製備可撓式染料敏化太陽能電池之半導體電極，探討電氣紡絲與電泳沉積的製程參數對可撓式染料敏化太陽能電池光電特性之影響，以往的可撓性染料敏化太陽能電池研究中，並沒有對可撓式電池反覆彎折後之機械、光電特性進行測試及探討，本研究中開發以相同曲率半徑連續彎折的方式比較彎折前後光電特性之變化。 由研究結果顯示，傳統製備半導體電極的方式在經過曲率半徑10mm，100次的彎折之後，TiO2層會有碎裂的情形導致電池導致效率下降95%甚至失效，而電氣紡絲製備之電池在彎折後下降70%，電泳沉積製備方法下降50%，但依然可以正常運作。電氣紡絲中TiO2濃度的提高，電池之光電轉換效率也會提高，以本實驗參數20%為最佳實驗參數。電氣紡絲與電泳沉積之膜厚均有一限度，電氣紡絲約為100微米，電泳沉積為12微米。以此兩種方法製備之電池在經過彎折後，光電轉換效率的降幅都比傳統方法來得小。

In recent years, the development of dye-sensitized solar cells (DSSC) produced considerable research interest, including improving efficiency, packaging and flexible possibilities. Flexible possibility has great potential for all kinds of applications. Researches on the bendability of the solar cell thin sheets are mostly focus on the making the soft substrate or electrodes. Previous studies showed that coating method of TiO2 semiconductor electrodes cracked after bending. This phenomenon makes the DSSC efficiency and lifetime substantially decline. This study used a flexible conductive material (ITO-PET) as substrate. The semiconductor electrode were prepared by electrospinning and electrophoretic deposition (EPD) method. After bending test, we observe the morphology and electrical properties of semiconductor electrodes. The photocurrent-voltage characteristics of assembled the DSSC were measured by Luzchem Solar Simulator (standard AM 1.5). Results of flexible DSSC indicated that ductility of electrospinning fibers and adhesion of electrophoretic deposition film enable the flexible solar cells after bending to avoid fragmentation of semiconductor electrodes. After bending 100 times, the efficiency of DSSC prepared by electrospinning decreased by 70%, and prepared by EPD decreased by 50%. They were still a functioning dye-sensitized solar cell.