電沉積氧化鋅薄膜應用在染料敏化太陽能電池之研究

Electrodeposition of Zinc Oxide Thin Films and Their Application in Dye-Sensitized Solar Cells

李威德(Wei-De Li)

指導教授 ： 余琬琴

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00407

摘要

近幾年，氧化鋅成為另一個可替代二氧化鈦在染料敏化電極的新式材料。因為，氧化鋅是一種寬能隙帶(3.37 eV)和較大激發鍵結能(60 meV)的半導體，且擁有獨特的光電性質。
利用含有鋅鹽之水溶液在導電基板上電化學沉積氧化鋅最近備受矚目，藉由電沉積過程，我們可以得到不同形狀和大小的氧化鋅，而且這個方法可以增強氧化鋅薄膜與基板的連結性，避免了高溫燒結這個步驟，使得基板選擇性變大，不需要熱穩定性超過150°C就可使用。此外，利用低溫溶液沉積擁有許多優勢，像是製程簡易、具有在線性、成本低廉和製備大面積薄膜及良好方向排列的氧化鋅。
本論文嘗試以電化學沉積方式沉積一維氧化鋅奈米柱及二維氧化鋅奈米片，透過三用電極裝置，控制不同電解液濃度、電位、時間和溫度，在導電玻璃(FTO)生長具優勢方向且擁有高表面積的奈米氧化鋅，再以不同燒結溫度製作電池元件，並經由量測光電轉換效率等性質去探討電沉積氧化鋅在電池元件上的效應，以期許能製成具高效率且穩定性高的染敏電池。

關鍵字

氧化鋅 ； 染料敏化太陽能電池 ； 陰極電沉積

並列摘要

Recently, zinc oxide (ZnO) has seen a renaissance as an important alternative to TiO2 in the use as a dye-sensitized electrode material, because ZnO is a wide band gap (3.37 eV) semiconductor with a large exciton binding energy (60 meV), and possesses unique optical and electronic properties.
The cathodic electrodeposition of crystalline ZnO from aqueous solutions of Zn2+ salts onto conductive substrates has become an important method. Depending on the deposition conditions, crystals of different shape and size were obtained. This method allows preparation of films with good contact among the ZnO crystals in the growth direction perpendicular to the substrate, so that any subsequent annealing steps can be avoided. A variety of substrates can be used as back contacts without the requirement of thermal stability beyond 150°C. Moreover, the low-temperature solution deposition method has several advantages such as simplicity, reproducibility, cost effectiveness, and suitability for producing large-area, highly oriented thin films.
In this study, cathodic electrodeposition method was employed for the preparation of crystalline ZnO thin films with highly oriented nanostructure. The effects of electrodeposition temperature, electrolyte concentration, electric potential, and electrodeposition time were investigated. The as-gown ZnO thin films were studied as dye-sensitized solar-cell electrodes, and photoelectron conversion efficiencies of the resulting cells were determined.

並列關鍵字

zinc oxide ； dye-sensitized solar-cell ； cathodic electrodeposition

參考文獻

3. M. Grätzel, K. Kalyanasundaram, Curr. SCi. vol. 66, 706 (1994).

6. M. K. Nazeeruddin, P. P’echy, M. Grätzel, Chem. Commun., 1705 (1997).

7. M. Gratzel, J. Photochem. Photobiol., vol. 3, 164 (2004).

9. S. Ferrere, A. Zaban, B. A. Gregg, J. Phys. Chem. B., vol. 101, 4490 (1997)

11. P. Guo, M. A. Aegerter, Thin Solid Films, vol. 351, 290 (1999).