高分子及其蒙托石奈米複合材料在膠態光敏型太陽能電池上的應用

Application of Polymers and Their Exfoliated MMT Nanocomposities on Gel-type Dye-sensitized Solar Cells

翁頂翔(Ting-Hsiang Weng)

指導教授 ： 林金福

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.03333

摘要

本研究首先是利用無乳化聚合方法製作出脫層片狀蒙托石水溶液，並利用各種儀器如TGA、FTIR、TEM、AFM等，量測其結構和性質。同時，吾利用透析方法除去片狀蒙托石溶液中多餘之離子，並量測其電導質，由電導值對濃度之關係，吾可以探討蒙托石水溶液中濃度對解離程度之影響。吾將脫層片狀蒙托石水溶液純化並除水後，藉由液態乙腈電解質之加入，並利用真空濃縮方法即可製成膠態電解質溶液。接著，將探討膠態電解質系統對於染料敏化二氧化鈦太陽能電池效能的影響。同時，吾利用了液態乙腈電解質及Ionic Liquid電解質來製作數個電解質系統當對照組，以期待找出能夠維持液態元件的高光電轉化效率，且能改善液態元件的封裝問題之最適合材料。
經由量測膠態電解質的導電度，以及對膠態系統元件作交流阻抗分析，可得知離子在電解質中的導電效果以及元件中的阻抗分布。量測的結果可發現PMMA電解質系統有較高的導電度與較好的離子擴散速率，而純化過之片狀脫層蒙托石電解質系統同時也具有不錯之電導度。換言之，當利用PMMA或脫層片狀蒙托石做電解質時，均可得到不錯之效率。
以元件的表現來看，液態乙腈電解質系統在入射光能量為100mW/cm2的光電轉換效率可達8.14%，短路電流值也可高達18.096mA/cm2。而膠態電解質系統中，以PMMA電解質系統的表現最好，有高達5.31%的光電轉換效率。次高的為純化過之脫層片狀蒙托石電解質系統，其效率可達5.29%。其中，表現最差的就是由Mica gel製程之Ionic Liquid電解質系統，其效率僅有2.69%，所以吾認為Mica gel在電解質中不會產生解離，因此效率不佳。

關鍵字

染料敏化太陽能電池 ； 高分子–蒙托石複合材料 ； 膠態電解 ； PMMA ； Ionic Liquid ； Mica gel

並列摘要

The first step of this research was to make the exfoliated Montmorillonite (MMT) nanoplatelet solution by soap-free emulsion polymerization, and to investigate the morphology and properties with TGA、FTIR、TEM、and AFM. We removed the unnecessary ions in solution by dialysis process, and measured the conductivity. From the relationship between conductivity and concentration, we could realize the concentration effects of MMT solution on the degree of dissociation. After purifying and removing water, we added liquid acetonitrile electrolyte to the exfoliated MMT nanoplatelets to prepare the gel-type electrolyte system. Then, we investigated the effects of the gel-type electrolytes on the performance of dye-sensitized titanium oxide solar cell. At the same time , we utilized both liquid acetonitrile electrolyte and ionic liquid electrolyte to make several electrolyte systems for comparison in order to find suitable materials for higher performance and better sealing properties of the solar cell devices.
The performance of electrolytes for gel-type devices could be estimated by measuring the conductivity and using EIS (Electrochemical Impedance Spectroscopy). As a result, we found that the PMMA electrolyte system (PMMA /ACN/LiI/I2/TBP) had higher conductivity and ionic diffusion rate. Also, the purified exfoliated MMT nanoplatelet electrolyte system had better conductivity. In other words, when utilizing electrolyte systems were with PMMA or exfoliated MMT nanoplatelets, we could obtain better efficiency.
In terms of the performances of devices, the photon-to electron power conversion efficiency of liquid ACN electrolyte (ACN/LiI/I2/TBP) was 8.14%, while the short-circuit current was 18.09 mA/cm2. For gel-type electrolyte system, the PMMA electrolyte system had the best performance and its efficiency could reach to 5.31%. The second highest efficiency was exfoliated MMT nanoplatelet electrolyte system, which could reach to 5.29%. The worst of all was mica gel ionic liquid electrolyte system, which just had 2.69%.Therefore, we think that mica gel had the poorest efficiency for not dissociating in ionic liquid.

並列關鍵字

dye-sensitized solar cell ； polymer-MMT composite ； gel-type ； PMMA ； Mica gel ； Ionic Liquid

參考文獻

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