低溫製備二氧化鈦光電極及其在可撓式染料敏化太陽能電池之應用

Low-temperature fabrication of titanium dioxide photoanode and its application in the dye-sensitized solar cells

王翔永(Shiang-Yung Wang)

指導教授 ： 戴念華

國立清華大學/工學院/材料科學工程學系/碩士(2012年)

摘要

本實驗選用聚乙烯對苯二甲酸酯(Polyethylene terephthalate, PET)進行電極製備，但因PET基板熔點約為2000C，無法應用於傳統4500C的高溫製程，故本實驗使用低溫燒結製程製備TiO2電極，並添加四異丙基鈦(Titanium isopropoxide, TTIP)作為漿料的連結劑(Binder)，電極經低溫1500C燒結後，可減少裂縫生成並且增加二氧化鈦顆粒間的黏著性 。為提升低溫製程電池的效率，本研究嘗試添加不同尺寸及含量的聚苯乙烯球(Polystyrene, PS microsphere)於低溫漿料中，並藉由N-甲基2-四氫吡各酮(N-Methyl-2-pyrrolidone, NMP)及不同溶劑清洗，移去PS球以改變多孔電極的微結構。最後將電極組成電池後，進行電池的量測。
本研究發現添加250 nm PS球於二氧化鈦電極中，經過有機溶劑NMP處理並以不同溶劑清洗，最後組合電池量測，可使光電轉換效率(Photo-electric conversion efficiency)由原本未添加PS球的電極所組成電池的量測效率為2.40%提升至3.23%，開路電壓則由0.73 V提升至0.92 V。添加PS電極之光電轉換效率雖略低於高溫製程所得的電池3.88%(玻璃基板)。但與未添加PS球的低溫漿料電池相比，效率已有明顯提升。最後比較彎曲測試(Bending test)下的電池效率，當電池彎曲至60o時，仍能維持2.82%的效率。

關鍵字

低溫製程 ； 可撓式二氧化鈦電極

並列摘要

In this study, we used polyethylene terephthalate (PET) as the electrode supporter of a flexible dye-sensitized solar cell (DSSC). Because PET can not sustain a high temperature of 4500C during the sintering process, therefore we developed a method to fabricate TiO2 photoanode for flexible DSSC which can be sintered at relatively low temperature. Tetraisopropoxide (TTIP), an additive which can increase interconnection of TiO2 particles at low sintering temperature, was introduced to TiO2 paste. To reduce the recombination of injection electrons, different sizes of polystyrene sphere were added to the TiO2 photoanode. The PS spheres were removed by NMP solution and then cleaned using different solvents. We found that the flexible DSSC with the efficiency of 3.23% can be attained when 250 nm PS spheres were added to TiO2 photoanode. In addition, the open circuit voltage is increased from 0.73 V to 0.92 V as compared with the photoanode without adding PS spheres. The efficiency of the cell under bending was tested and an efficiency of 2.82% was obtained at the bending angle of 60o.

並列關鍵字

low temperature fabrication ； flexible titanium dioxide

參考文獻

[15] P. Yao, L. Wang, E. Chiang, K. Ho, Y. Chen, “Nanocrystalline TiO2 for porphyrin-sensitized solar cells: a preliminary study”, Journal of Science and Engineering Technology, l 4 (2008) 35–42.

[2] V. Gray, et al, “Climate Change 2007：The Physical Science Basis Summary for Policymakers”, IPCC 4th Assessment Report (2007).

[3] G. Kukla, T. R. Karl, “NIGHTTIME WARMING AND THE GREEN HOUSE EFFECT”, Environmental Science Technology, 27 (1993) 1468–1474.

[6] G. E. Tulloch, “Light and energy–dye solar cells for the 21st century”, Chemistry, 164 (2004) 209–219.

[7] K. Hara, N. Koumura, “Organic dyes for efficiency and stable dye-sensitized solar cells ”, Material Matters, 4 (2009) 92.