臺灣博碩士論文加值系統

在本研究中，我們使用商用光學模擬軟體FRED並利用光線追跡 (Ray Tracing) 技術，模擬表面織構散射結構，探討不同參數的情況下的光學特性。首先討論不同的散射體直徑對於四種入射光波長550nm、700nm、900nm及波長1200nm，從霧度及等效光程長度比來探討散射效果的優劣，進而確定適用於非晶矽太陽能電池的散射體尺寸的分佈範圍。並再就散射體的覆蓋密度作探討，發現其覆蓋密度會與等效光程長度比呈線性關係。而後模擬在不同入射光波長的主動層吸收率，換算為外部量子效率，並且分別探究單接面(Single junction)以及疊層(Tandem)電池，單接面電池主動層材料使用a-Si:H (氫化非晶矽)而疊層則是增加了μc-Si:H (氫化微晶矽)，再計算出在標準太陽光譜下的光電流及光電轉換效率。
模擬出的結果，在單接面電池的部分，最佳尺寸我們設定為0.05μm(+/-5%)，結果顯示，散射層可讓光電流值與光電轉換效率都增加約12%。另外在疊層電池方面，我們選用兩種不同的散射體尺寸做比較，分別為0.055μm(+/-5%)以及0.075μm(+/-5%)，從模擬結果得知，與無散射層的模型比較，其散射層讓短路電流密度分別增加了25.7%與22.0%，並都達到了15%的光電轉換效率。

In this work, we used commercial optical simulation software FRED to simulate surface-textured solar cells and to study the optical properties under various conditions. First we studied the scattering efficiency in terms of haze and equivalent optical path length factor as a function of scatter size for four incident light wavelengths: 550nm, 700nm, 900nm and 1200nm.Thus the ideal range in scatter size for silicon thin-film solar cells was obtained. After that, we studied and found a linear relationship between the surface coverage percentage of scatters and the equivalent optical path length factor. Then we carried out the simulations of single-junction and tandem cells respectively and obtained the absorptance of the active layers versus incident light wavelength. The materials used for the single junction and tandem cells were a-Si: H (hydrogenated amorphous silicon) and μc-Si: H (hydrogenated microcrystalline silicon), respectively. Consequently the external quantum efficiency versus incident wavelength, the short-circuit current density and the energy conversion efficiency can be obtained under standard 1-sun AM1.5G solar spectrum.
In the single-junction cell simulation, the ideal scatter size chosen was 0.05μm (+ / -5%), and the results showed that the scattering layer improved both the short-circuit current density and the conversion efficiency by about 12%. In the tandem cell simulation, compared to the one without scatters, the two tandem cells with different scatter sizes of
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0.055μm (+ / -5%) and 0.075μm (+ / -5%) helped increase the short-circuit current density by 25.7% and 22.0%, respectively, and both have reached 15% in conversion efficiency.

摘要 .......................................................................................................... I
Abstract ................................................................................................. II
致謝 ........................................................................................................ IV
目錄 ......................................................................................................... V
圖片目錄 .............................................................................................. VIII
表格目錄 .............................................................................................. XIII
第一章 導論 ........................................................................................ 1
1.1太陽能電池現況 ....................................................................... 1
1.2 文獻回顧 ................................................................................. 4
1.3 研究方向與目的 .................................................................... 11
第二章 原理介紹 ................................................................................. 13
2.1 太陽能電池............................................................................ 13
2.1.1 太陽光譜 .................................................................... 13
2.1.2 太陽電池原理 ............................................................ 15
2.1.3量子效率 ..................................................................... 19
2.2 散射理論 ............................................................................... 21
第三章 實驗方法 ................................................................................. 25
3.1 光學模擬軟體FRED之簡介與概論 ....................................... 25
VI
3.1.1 FRED簡介 ................................................................... 25
3.1.2 FRED各項參數概述 ................................................... 26
3.2模擬模型設定 ......................................................................... 39
3.2.1設定光源 ..................................................................... 40
3.2.3設定樣品結構與材質 ................................................. 40
3.2.3設定電池層 ................................................................. 43
3.3模擬軟體使用中的問題與解決辦法 ...................................... 44
3.3.1鑲嵌散射體 ................................................................. 44
第四章 結果與討論 ............................................................................. 48
4.1球型散射體最佳化尺寸 ......................................................... 48
4.1.1霧度與等效光程長度比之分析 .................................. 48
4.1.2 散射體材料之分析 .................................................... 53
4.2 入射光受散射體密度影響 .................................................... 57
4.2.1 擴散穿透率(Diffuse transmittance)與霧度(Haze)隨覆蓋密度之分析 ................................................................ 57
4.2.2散射光角度分佈隨散射體密度之分析 ...................... 62
4.3非晶矽薄膜太陽能電池之模擬分析 ...................................... 66
4.3.1 矽薄膜太陽能電池模型介紹與其模擬結果 ............. 66
4.3.2 材料吸收率對外部量子效率之影響 ......................... 87
VII
第五章 結論與未來展望 ...................................................................... 90
參考文獻 ............................................................................................... 92

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