氧化鋅複合式奈米結構應用於可撓式染料敏化太陽能電池

Fabrication of ZnO Composite Photoanode on Dye Sensitized Solar Cell

施力綺(Li-Chi Shih)

指導教授 ： 閔庭輝

國立虎尾科技大學/電機資訊學院/電子工程系碩士班/碩士(2015年)

https://doi.org/10.6827/NFU.2015.00142

摘要

本研究以水熱法製備低密度的氧化鋅微米柱在無晶種層的ITO/PEN可撓式基板上，其微米柱長度約為14μm左右，之後再使用刮刀塗佈法將直徑約為20nm的氧化鋅奈米粒子塗佈於微米柱之間。氧化鋅微米柱(NPs/MRs)複合電極再經過機械加壓418kg/cm2，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，進而提高入射光與氧化鋅奈米粒子之間的碰撞機率；而氧化鋅粒子薄膜可以吸附染料進而提升光電流，因此氧化鋅微米柱(NPs/MRs)複合式結構可以有效提升染料敏化太陽能電池整體的光電流轉換效率。藉由分析中得知，當氧化鋅薄膜厚度增加時，光電特性隨之提升，其主要原因與染料吸附量有關，當氧化鋅粒子薄膜厚度增加，染料吸附量也跟著增加，經照光後染料所激發的電子增加，使得阻抗下降。
本實驗對單純氧化鋅粒子薄膜進行機械壓縮與薄膜厚度分析，並發現在機械壓力418kg/cm2下有著33μm薄膜厚度，浸泡D149染料後有最佳
的太陽能轉換效率2.90%，且將研究出來的最佳機械壓力與薄膜厚度應用於複合式電極中。為了製備複合式結構的染料敏化太陽能電池，本實驗在不同溫度與不同時間下生長氧化鋅微米柱陣列薄膜，改變水熱生長溫度不僅影響氧化鋅微米柱改善電極表面的形貌，而不同的水熱生長時間，會影響氧化鋅微米柱的長度，本篇發現在氧化鋅微米柱長度為14μm搭配33μm時會有較佳的電性也表現出較高的氧化鋅複合式結構染料敏化太陽能電池效率3.46%。

關鍵字

氧化鋅 ； 氧化鋅微米柱 ； 複合式結構 ； 水熱法 ； 染料敏化太陽能電池

並列摘要

In this study, we prepared low-density zinc oxide micron rods (MRs) on the non-seed layer ITO/PEN by hydrothermal. The analyses of field emission scanning electron microscopy show that the average length of the zinc oxide micron rods is 14μm, then used the scraper method to fill the ZnO nanoparticles into the micron rods to prepare the photoelectrode. Zinc oxide micron rods (NPs/MRs) composite electrode was pressed under 418kg / cm2 through mechanical pressure, these improvements are attributed to the multiple functions of the composite structure, including large surface area for sufficient dye adsorption, micron rods for efficient light scattering, and one-dimensional building units for longer electron lifetime. Light-scattering layer can effectively increase the traveling path of incident light, thereby increasing the collision probability between the incident light and the zinc oxide nanoparticles. The zinc oxide nanoparticles film can absorb dye to enhance the photocurrent, therefore zinc oxide micron rods (NPs/MRs) composite structures can effectively enhance the overall dye-sensitized solar cell photocurrent conversion efficiency. From the analysis, with the thickness of zinc oxide film increase, the optical properties will also increase. This is mainly due to the amount of the dye adsorption, when the thickness of the zinc oxide film increase, the dye adsorption will also

increase, after illumination, the dye excited electrons increase, this result indicates that the resistivity decrease. From this research, we press and analysis the zinc oxide particles film under mechanical pressure, we found that under 418.8kg/cm2 mechanical pressure the ZnO film achieve the thickness of 33.0μm. After immersed the D149 dye has the best conversion efficiency for dye-sensitized solar cells (DSSCs), which is 2.90%. This result will come up with the best mechanical pressure and thickness of the film then applied to the composite electrode. In order to prepare the composite structure of DSSCs, we use different growth temperature and different time to prepare ZnO micron rods. The growth temperature not only affects the crystalline of zinc oxide, but also improves the surface morphology of the electrode, and different growth time will affect the length of zinc oxide by hydrothermal. The best photoelectric conversion efficiency was found to be 3.46% with the composite structures.

並列關鍵字

ZnO ； ZnO micron rods ； composite structures ； hydrothermal method ； dye sensitized solar cell

參考文獻

[33] C.-S. Lin.,2009 , “The Synthesis of Tetrapod Zinc Oxide Whiskers and the Influence of Calcination on Optical Property”, Chemistry, 67 (2),207-213.

[42]林明獻，2007，“太陽能電池技術入門”, 第二章.

[51]范俊豪,2013, “氧化鋅奈米柱與奈米薄膜雙層結構應用於可撓式染料敏化太陽能電池之研究”

[68]張溏芸，2014，”金奈米粒子鑲埋於染料敏化太陽能電池光電極之研究” ，國立虎尾科技大學電子工程系碩士論文。

[71]郭建麟，2010，“功能性氧化鋅奈米材料的成長與光電性質” 。