奈米粒與微米柱複合結構在染料敏化太陽能電池的應用

Nanoparticle-Microrod Composite Photo-Anode for Dye-Sensitized Solar Cells

吳東龍(Tung-Lung Wu)

指導教授 ： 蔡振凱

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2011年)

摘要

本研究以水熱法成長低密度氧化鋅微米柱在無晶種層的FTO與ITO玻璃上，其氧化鋅微米柱直徑約為1 μm，之後再利用刮刀塗佈法將直徑約為25 nm的二氧化鈦奈米粒子刮於微米柱之間。氧化鋅微米柱(NPs/MRs)複合電極再經過加壓處理後，其中氧化鋅微米柱狀結構作為光散射層及光電子快速傳輸路徑；光散射層能增加入射光的行走路徑，進而提高入射光與二氧化鈦粒子之間的碰撞機率；而二氧化鈦奈米粒子可以吸附更多的染料進而提升光電流，因此氧化鋅微米柱(NPs/MRs)複合電極可以有效提升染料敏化太陽能電池之特性。由EIS分析中得知，當二氧化鈦薄膜厚度增加時，Rk的電阻值就變小，其主要原因是跟染料吸附量有關，薄膜厚度的增加，染料吸附量也就越多，照光後染料激發之電子增多，使得電阻值下降。由效率分析中得知二氧化鋅微米柱(NPs/MRs)複合電極之染料敏化太陽能電池最高為6.45 %與相關文獻之效率要高出許多，但仍遠低於純二氧化鈦奈米光電極之染料敏化太陽能電池，因為所用之釕系染料並不適合氧化鋅微米柱，而本論文所製作的純二氧化鈦奈米光電極之染料敏化太陽能電池最高效率達10.34%。

關鍵字

氧化鋅 ； 二氧化鈦 ； 染料敏化太陽能電池

並列摘要

In this study, the composite photo-anode of TiO2 nanoparticles (NPs) and ZnO microrods (MRs) was fabricated on fluorine-doped tin oxide (FTO) and indium tin oxide (ITO) glass. ZnO MRs, diameter of 1 μm, grown by hydrothermal method on free seed FTO glass, followed by Doctor blade of TiO2 NPs, diameter of 25 nm, on the MRs surface. The columnar structure of ZnO MRs as a light scattering layer and a channel for transmit rapidly the photoelectron. Light scattering layer can increase the path length of the incident light and enhances the collided probability between the incident light and the TiO2 NPs. TiO2 NPs has large surface area to absorb dye and thus enhance the light current. Therefore, the TiO2 NPs and ZnO MRs composite photo-anode can enhance the features of dye sensitized solar cells. In the electrochemical impedance spectroscopy (EIS) analysis, the value of Rk decreases with increasing the thickness, the primary cause is related with the dye adsorptive capacity. It may be due to the stimulation of illumination for the electron in the dye, resulting in the reduced of the Rk. Under the irradiation of the sunlight simulator (AM 1.5, 100 mW/cm2), the dye-sensitized solar cells (DSSCs) of composite photo-anode up to 6.45 % with the literature of the much higher efficiency, but still much lower than that of DSSCs suing pure TiO2 photo-anode, because the use of the ruthenium dye is not suitable for ZnO. In this study, the highest efficiency of pure TiO2 NPs photo-anode DSSCs, the thickness was up to 23 μm, was up to 10.34 %.

並列關鍵字

ZnO ； Tio2 ； Dye-Sensitized Solar Cells

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