以化學水溶液法合成多形貌氧化鋅奈米結構及其於染料敏化太陽能電池之應用

Abstract

在本研究中，我們利用化學水溶液法(Chemical solution method)合成氧化鋅奈米結構，運用化學水溶液法製程低溫、簡單的特性，簡便的合成氧化鋅材料，並藉由調配不同有機胺的成分比例，達成不同形貌的氧化鋅奈米結構，其中包含氧化鋅奈米線(ZnO nanowire)、無基板氧化鋅奈米線薄膜(Substrate-free ZnO nanowire film)、星狀氧化鋅奈米顆粒(Star-like ZnO nanoparticles)，我們分別探討反應時間對各結構的成長厚度及型態的影響。材料特性鑑定方面，透過SEM、X光繞射分析、氮氣等溫吸附等方法，來探討三種不同形貌的氧化鋅奈米結構、結晶方向、比表面積及孔隙率等。本研究也分別利用上述三種氧化鋅奈米結構，結合商用N719染料、I-/I3-碘系電解液及鉑相對電極組裝成染料敏化太陽能電池，經太陽能電池特性測量，氧化鋅奈米線工作電極擁有最高1.9%的光電轉換效率，並產生8.54mA/cm2的短路電流，同時也分析比較各結構之差異。入射光子-電流轉換效率(IPCE)方面，測得最高IPCE轉換效率為26.85%。本研究也從電化學交流阻抗圖譜去分析各結構對於染料敏化太陽能電池的阻抗影響，透過等效模型來驗證氧化鋅在電子擴散速率上的優勢。

In this work, we present three ZnO nanostructures synthesized by chemical solution method. Solution approaches to synthesize ZnO nanostructures are appealing because of their low growth temperature and good potential for scaling-up. By modifying different Amine ingredients, three types of ZnO nanostructures were grown, including ZnO nanowire array, substrate-free ZnO nanowire film, and Star-like ZnO nanoparticles. The influences of reaction times on the thickness and morphology of nanostructures were also presented. The XRD patterns showing highly diffraction intensity in z-direction ZnO nanowire were observed. The development of dye-sensitized solar cell utilized these nanostructures as photo anodes were presented. The dye-sensitized solar cell comprises a FTO glass with dense ZnO nanostructures as working electrode, a platinized FTO glass as counter electrode, N719-based dye, and I-/I3- liquid electrolyte. The dye-sensitized solar cell fabricated using such nanostructures yields a highest power conversion efficiency of 1.9% and the IPCE photo-current efficiency is up to 26.85%. Electrochemical impedance spectroscopy is applied to investigate the characteristics of dye-sensitized solar cells in this study. The improvement of the electron transport in the ZnO photo anode has also been demonstrated.