臺灣博碩士論文加值系統

本論文探討在結合多層膜與折射率漸變結構的概念下，將氧化鋅奈米柱以水熱法成長於二氧化鈦薄膜上，並理論計算出最佳之折射率匹配組合，用於提升磷化銦鎵/砷化鎵/鍺三接面串接式太陽能電池之光電功率轉換效率。本研究先透過橢圓儀分析，將氧化鋅奈米柱等效分成三層複數折射率之物理薄膜，再代入艾里方程式(Airy formula) 計算其整體光學反射率。實驗上，我們所提出之氧化鋅奈米柱/二氧化鈦複合式多層抗反射結構展現出極低的反射率(average reflectivity, Ravg~5.7%)，並具有全波段與對角度不敏感的特性，此與理論計算數值十分吻合。
我們更進一步地與傳統的雙層抗反射膜二氧化矽/二氧化鈦以及單純氧化鋅奈米柱作比較，發現在垂直入射的條件下，氧化鋅奈米柱/二氧化鈦抗複合式多層抗反射結構能使多接面太陽能電池其電流密度提升約31.3%，而二氧化矽/二氧化鈦及氧化鋅奈米柱僅分別有27.3% 與28.7%的提升。當太陽光入射角度增加至80度時，氧化鋅奈米柱/二氧化鈦複合式多層抗反射結構依然能在元件電流密度提升約35.2%；反之，氧化鋅奈米柱卻只有24.3%的提升，而二氧化矽/二氧化鈦抗反射層的提升更降低至9.4%。
因此，本論文所提出的結構，對於太陽能電池光電功率轉換效率的提升有極大的效益，且因對太陽光之入射角度不敏感，能提供較佳的封裝容忍度于後續的電池模組整合。此外，本論文結構製作容易且成本低廉，預期將能廣泛地應用於其他不同材料系統之太陽能電池結構。

In this study, we theoretically and experimentally demonstrate a novel antireflection coating (ARC) structure by hydrothermally growing ZnO nanorods (NRs) upon titanium dioxide (TiO2) layer to enhance the overall power-conversion efficiency of InGaP/GaAs/Ge triple junctions solar cells. It was shown that our proposed ZnO NRs/TiO2 hybrid structure exhibits excellent broadband and omnidirectional AR behaviors, and remarkably enhances the omnidirectional photovoltaic performance of solar devices. As compared to other conventional ARC structures, the proposed ZnO NRs/TiO2 hybrid ARC improves the short-circuit current (JSC) of the solar device to about 31.3% under the normal incidence of solar illumination, and those are enhanced to about 27.3% and 28.7% by employing the conventional SiO2/ TiO2 double layers and pure ZnO NRs ARCs, respectively. Significantly, such JSC enhancement of ZnO NRs/TiO2 hybrid ARC remains in still even the incident angle of solar light increases to 80°, whereas that reduces to only 24.3% and 9.4% for the conventional SiO2/ TiO2 double layers and pure ZnO NRs ARCs, respectively. Additionally, as the measured low-reflectivity on our ZnO NRs/TiO2 hybrid ARC is broadband and omnidirectional, it provides a great potential and tolerance for the subsequence package with photovoltaic modules, and could be directly applied to other kinds of solar cells with different composited materials.

摘要 I
Abstract III
謝誌 IV
目錄 V
表目錄 VIII
圖目錄 IX
第一章 序論與研究動機 1
(一) 太陽能源發展概況 1
(二) III-V 族多接面半導體太陽能電池發展現況 3
(三) 研究動機 4
參考文獻 8
第二章 理論背景及太陽能電池特性介紹 9
(一) 太陽能電池常用參數與定義 9
1. 太陽光譜 9
2. 光伏特效應(Photovoltaic effect) 11
3. 短路電流密度(Short-circuit current density, Jsc) 12
4. 開路電壓(Open Circuit Voltage ,VOC) 13
5. 填充因子與能量轉換效率 14
6. 量子效率(Quantum efficiency, QE) 15
參考文獻 17
第三章 抗反射層原理 18
(一) 多層膜結構 18
(二) 折射率漸變結構(Gradient Refractive Index) 20
(三) 氧化鋅文獻回顧 23
第四章 抗反射層設計 30
(一) 材料選擇 30
1. 二氧化鈦(Titanium dioxide, TiO2) 31
2. 二氧化矽(Silicon dioxide, SiO2) 31
(二) ZnO奈米柱成長 32
(三) 多接面太陽電池之限制電流層 33
(四) 抗反射層設計 36
(五) 太陽能電池效率計算 38
參考文獻 41
第五章 實驗製作與量測 42
(一) 雙層抗反射膜製作 42
1. 二氧化鈦(Titanium dioxide, TiO2） 42
2. 二氧化矽(Silicon dioxide, SiO2) 42
(二) 氧化鋅奈米柱與二氧化鈦 43
(三) 反射率量測 44
1. 鏡面反射 44
2. 漫射反射 46
(四) 電性量測 49
(五) 變角度反射率量測 51
(六) 變角度電性量測 53
第六章 結論 56

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