以含羥基釕金屬染料與奈米碳管改良之固態染料敏化太陽能電池製作及性質研究

Fabrication and Characterization of Solid-State Dye Sensitized Solar Cells Incorporating Hydroxy-attached Ruthenium Dye and Carbon Nanotubes

羅喬嶽(Chiao-Yueh Lo)

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(2012年)

https://doi.org/10.6342/NTU.2012.01844

摘要

本研究共分為三部分：1.固態染料敏化太陽能電池元件最佳化，2.羥基取代之釕金屬染料在固態染料敏化太陽能電池之應用，以及3.利用奈米碳管改質固態染料敏化太陽能電池之二氧化鈦多孔層。第一部分中，我們專注於最佳化固態染料敏化太陽能電池的二氧化鈦緻密層及多孔層厚度。藉由改變前驅物溶液之濃度，可控制生成之膜厚。我們得到的最佳厚度與製程參數，和文獻上吻合。
　　在第二部分中，我們合成一羥基取代之釕金屬染料RuC1OH，製作並分析使用RuC1OH作為光敏材料的固態染敏太陽能電池。與N3染料相比，這些元件擁有較高的開路電壓與短路電流，其效率可達1.01%。進一步，利用交流阻抗分析(EIS)、IMPS/IMVS、光電壓衰減與電量收集法探討元件之光電性質。二氧化鈦表面特性、電洞傳導材料在多孔層中的孔洞填充率則使用SEM技術分析。我們認為光電效率的提升可歸結於RuC1OH改善了多孔二氧化鈦之表面特性，使電洞傳導材料達到更高的孔洞填充率。
　　在第三部分中，先將奈米碳管以NaPSS改質後，加入固態染敏太陽能電池之多孔二氧化鈦層。由XRD圖譜中，計算得知加入碳管能提高二氧化鈦之anatase相比例。我們並觀察到，較高之二氧化鈦anatase比例，不僅能提升液態染敏太陽能電池之元件效率，對固態染敏太陽能電池系統也有正面幫助。雖然開路電壓略微下降，但可從短路電流與fill factor之提升得到補償，光電轉換效率從0.75%提升到0.94%。進一步利用交流阻抗分析(EIS)和IMPS/IMVS，我們發現加入奈米碳管使電子電洞復合速率與電流傳導速率皆上升。
　　總結而言，二氧化鈦表面性質會受到吸附染料性質影響，且是電洞傳導材料孔洞填充率的重要變因。另一方面，在固態染敏太陽能電池之多孔性二氧化鈦電極中摻入奈米碳管，與在液態電解質系統中一樣可提升元件之光電轉換效率。

關鍵字

固態染料敏化太陽能電池 ； 緻密層 ； 多孔性二氧化鈦 ； 孔洞填充率 ； 表面改質奈米碳管 ； 銳鈦礦 ； 電子傳遞

並列摘要

This research is divided in three parts: 1. fabrication optimization of the solid-state dye sensitized solar cells (SSDSSCs), 2. application of hydroxyl-substituted ruthenium dye on SSDSSCs and 3. incorporating MWCNTs in TiO2 working electrode for SSDSSCs . We first carried out the fabrication optimization of SSDSSCs by adjusting the compact layer and nanoporous layer thickness. The thickness of each layer was controlled by varying the concentration of precursor solution. The optimized processing parameters matches those reported in the literatures.
In the second part, we have synthesized a hydroxy-substituted dye, denoted as RuC1OH. SSDSSCs sensitized with RuC1OH were fabricated and characterized. The SSDSSCs based on RuC1OH performed both higher open-circuit voltage and short-circuit current compared to N3 based devices. The power conversion efficiency (PCE) reached 1.01%. Photovoltaic properties were characterized by electrochemical impedance spectroscopy (EIS), IMPS/IMVS, photovoltage decay, and charge collection techniques. The surface properties of TiO2 and hole-transport material infiltration were studied by contact angle measurements and SEM, respectively. The photovoltaic property improvement can be attributed to higher affinity between RuC1OH sensitized TiO2 and hole-transport material (HTM), which lead to better HTM infiltration into nanoporous TiO2.
In the third part, MWCNTs were surface-modified by NaPSS and added to the nanoporous TiO2. According to XRD results, the anatase phase of TiO2 increased when MWCNT was added. We observed that more anatase phase benefits photovoltaic properties of SSDSSCs. Although the open-circuit voltage decreased with the addition of MWCNT, it was compensated by higher short-circuit current and higher fill factor. The PCE increased from 0.75% to 0.94%. The device properties were further characterized by EIS and IMPS/IMVS, and the results showed that both recombination rate and charge transfer rate were increased.
In summary, the TiO2 surface properties can be tuned by different sensitizers, which is important for improving HTM pore-filling. We also found out that introducing MWCNTs could improve the PCE of SSDSSCs.

並列關鍵字

solid-state dye sensitized solar cell ； compact layer ； nanoporous titanium dioxide ； pore filling ； surface-modified carbon nanotube ； anatase phase ； electron transport

參考文獻

102. 葉珈妏, 陰離子物理吸附多層奈米碳管在染料敏化太陽能電池光電極之應用, 臺灣大學高分子科學與工程學研究所碩士學位論文2012, 臺灣大學. p. 1-173.

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