水對於染料敏化太陽能電池劣質化之分析研究

The influence of water to the degradation of the dye-sensitized solar cells

鄭汀佑(Ting-Yu Cheng)

指導教授 ： 楊重光

國立臺北科技大學/工程學院/化學工程研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00183

摘要

本論文是以原位傅立葉散射–反射紅外光譜儀探討染料分子(N719、N3、N749)及電解液添加劑吸附於TiO2薄膜表面的吸附形態。水在劣質化的過程中是相當重要的角色，在本研究中將對電池元件劣質化分為三大部分討論：1. 將吸附完染料分子之TiO2薄膜浸入含水的電解液中；2. 進行染料劣質化分析及動力學的探討；水導致電解液的添加劑析出之劣質化分析；3. 水影響太陽電池元件的光電轉換效率、開路電壓、短路電流及填充因子的變化情形。
研究中發現染料分子的鍵結型式均是以雙牙配位或者以橋接配位形式鍵結。在充滿電解液的電池元件中，鋰離子會嵌入或吸附於TiO2薄膜表面，使得電解液中的添加劑更容易地吸附於TiO2薄膜表面，因此提升太陽能電池元件的開路電壓並且有效地抑制暗電流的產生。染料分子的配位基SCN-在劣質化過程中為一重要角色，因此將利用SCN-的ν (CN)劣質化程度進行擬一階動力學分析。
由結果中得知從染料斷鍵的SCN-官能基在薄膜表面會與Li+離子形成Li–NCS鍵結。然而過量的水則會讓吸附於薄膜表面的染料分子脫落，並且會讓電解液中的固態添加劑以(MBI-H+)2(I-)2方式析出。從動力學分析中則可發現染料N749不管在水或同位素水中的劣質化速率都比染料N719及N3來的慢。

關鍵字

染料敏化太陽能電池 ； 染料分子劣質化 ； 電解液添加劑

並列摘要

This study was analysed the dyes molecular (N719、N3、N749) and additives of electrolyte were adsorbed on TiO2 film by In-situ DRIFTs. Water plays an important rule in dyes degradation process, the degradation of the dye-sensitized solar cells by water was studied from three parts : 1. working electrode was degraded by water and found out degradation mechanism of dyes molecular and substitution kinetics. 2. water leaded to additives of electrolyte regeneration. 3. DSSCs properties were influenced by the electrolyte with different water content.
The interaction between N719, N3, and N749 with TiO2 films were investigated by In-situ DRIFTs spectroscopy. The results show that the dyes were anchored onto the TiO2 surface by bidentate or bridging mode. When the cells were teeming with electrolyte, Li+ ions were inserted into TiO2 surface. Therefore, additives adsorbed strongly on TiO2 surface. Besides, the value of Voc was enhanced by additives in electrolyte and averted the dark current formation effectively. The SCN- ligand was played an important ligand in dyes molecular, and degradated at room temperature (25C) by means of a simple slow-pseudo first-order reaction.
Our study indicates that Li–NCS on the TiO2 surface when the SCN- ligand was broken from dyes molecular. A surfeit of water resulted in dyes molecular de-adsorbed from the TiO2 surface, and formed slightly (MBI-H+)2(I-)2 crystals. Finally, the dyes N749 were degraded in water or isotope both of the degradation rate were slower than N719 and N3.

並列關鍵字

Dye-sensitized solar cells ； Dyes degradation ； Additives

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