氧化鋅奈米棒陣列/高分子太陽能電池研究

Abstract

本論文利用垂直成長於基板的氧化鋅奈米棒陣列來製備太陽能電池元件。太陽能電池運作時，產生的光電子能夠在規則垂直氧化鋅棒中做ㄧ維方向的傳輸，降低內電阻並減少再結合的機會。 我們使用溶膠-凝膠法在ITO基材上製備氧化鋅緩衝層,並使用低溫的水溶液合成法在緩衝層上合成出規則的氧化鋅奈米棒。利用不同的緩衝層膜厚、熱處理溫度、成長時間來得到不同的結構。 將溶液狀態的光電高分子塗佈於氧化鋅棒上，製作成有機太陽能電池元件。使用掃描式電子顯微鏡、吸收光譜來分析元件的表面形態和內部結構。在地表太陽光模擬光源照射下以電性分析儀來分析太陽能電池的效率，並調整氧化鋅棒的長度、整體元件厚度等參數來獲得最佳的效果。在氧化鋅棒/規則性-聚(3-烷基噻吩)元件可以產生0.909 % 的能量轉換效率。並在460nm的波長有22 % 的外部量子效率。整體效率高過於氧化鋅膜/規則性-聚(3-烷基噻吩)雙層元件3倍以上。在聚3-烷基噻吩中加入均勻分散的PCBM可以有效的增加電子電洞分離的機率，並將效率提升至1.01%。

This research focus on the preparation of hybrid polymer/zinc oxide (ZnO) solar cells, in which the ZnO rods grown perpendicularly on ITO substrates, as a means to provide a direct and ordered path for photogenerated electrons to the collecting electrode. We use sol-gel method to fabricate ZnO backing layer and low-temperature solution-based growth techniques to grow ZnO nanostructures. Different backing layer thickness, heat-treatment condition, growth time were investigated for solar cell application .After deposit polymer, using scanning electron microscopy, absorption spectroscopy and photovoltaic device measurements to study the morphology and device performance of the prepared structures. The dependence of the photovoltaic performance on the ZnO nanorods length and the organic layer thickness was investigated. Under AM1.5(100mWcm -2) global solar condition, the best ZnO nanorods/ poly(3-hexylthiophene) photovoltaic device yields power conversion efficiency 0.909% and a peak external quantum efficiency 22% at 460nm. The power conversion efficiency of it is tree times as large as that of ZnO film/ regioregular poly(3-hexylthiophene) bilayer system. The ZnO / polythiophene device is limited in photocurrent due to the large spacing between the ZnO fibers. This is overcome by blending PCBM into the polythiophene film and can enhance power conversion efficiency to 1.01%.