臺灣博碩士論文加值系統

本論文研究了自組遮蔽乾式蝕刻矽奈米尖錐結構，與無電鍍金屬沉積蝕刻矽奈米線結構的的抗反射效果，並簡易地成功試製成之太陽能電池。我們發現，無電鍍金屬沉積蝕刻速率較自組遮蔽乾式蝕刻之蝕刻速率快約40倍。該兩種奈米結構都有寬帶抗反射效果，但比較上，奈米尖錐有比較好的效果。這是因為奈米尖錐可等效近似理想的漸進折射率結構所致。此部分，我們並使用有限差分時域方法，加以證實。
在製成太陽能電池過程中，經過擴散後，雖然兩種矽奈米結構都被明顯破壞，但仍維持比單晶矽基板較低的反射率。實驗顯示，奈米尖錐及奈米線，製成電池後，對比於矽單晶電池，其效率分別提升4倍與2倍之多。不過由於製程未最佳化，串聯電阻較大等因素，我們初步所製作之太陽能電池，效率與理想因子FF(Fill factor)仍低，有待進一步改善。

We have studied the anti-reflection property of two silicon nanostructures: the nanotips and the nanowires fabricated through self masked dry etching(SMDE) and electroless metal deposition etching(EMDE), respectively. Simple solar cells based on the two structures were also successfully demonstrated. The etching rate of EMDE was found to be 40 times faster than that of SMDE. Both the two structures show broadband antireflection properties, with the nanotips’ performance be better due to the equilibrium graded index of the structure.. The antireflection performance of nanotips is better for their acting as equivalent graded index, which have been verified using the finite different time domain method.
After boron diffusion for fabrication of solar cells, apparent structural damages on both nano-structures were observed. Nevertheless, the reflectivities of both nano-structures after diffusion were still lower than that of pure silicon wafer. The efficiency of the solar cells thus fabricated on silicon nanowires and nanotips showed two fold and four fold enhancement respectively, as compared to that of solar cells fabricated on pure silicon wafer. However, the efficiency and fill factors of solar cells thus fabricated were still far from perfect, due to the still simple structure as well as the high serial resistance of the solar cells, requiring further improvement in the future.

第一章 簡介 1
第二章 基本原理 3
2.1 自組奈米遮蔽乾式蝕刻技術之工作原理 3
2.2 無電鍍金屬沉積蝕刻技術之工作原理 4
2.3 太陽能電池的發展 6
2.4 太陽能電池原理 8
2.5 太陽能電池之等效迴路 9
2.6 太陽能電池之量測與效率計算 11
第三章 實驗方法與設備 16
3.1 實驗方法與步驟 17
3.1.1 基板製備 17
3.1.2 自組遮蔽乾蝕刻技術製作奈米尖錐 18
3.1.3 無電鍍金屬沉積蝕刻技術製作奈米線 18
3.1.3.1 蝕刻機制 18
3.1.3.2 製備奈米線參數 19
3.1.4 高溫爐擴散製程 20
3.1.4.1 氮化硼氧化 20
3.1.4.2 硼的擴散 21
3.1.4.3 熱探針檢測法 22
3.1.5 電流電壓曲線量測 23
3.2 實驗儀器簡介 24
3.2.1 電子迴旋共振微波電漿化學氣相沉積系統 24
3.2.2 濕蝕刻系統 25
3.3 表面結構與材料分析儀器介紹 26
3.3.1 掃瞄式電子顯微鏡 26
3.4 光學特性分析儀器介紹 27
3.4.1 光譜儀 27
3.5 高溫爐擴散系統 27
3.6 電性量測系統 28
3.6.1 濺鍍機製作電極 28
3.6.2 電流-電壓曲線量測儀器 28
第四章 結果與討論 30
4.1 矽奈米尖錐表面結構及抗反射特性 30
4.1.1 矽奈米尖錐之表面結構 30
4.1.2 自組遮蔽乾式蝕刻技術之蝕刻比率 31
4.1.3 矽奈米尖錐之抗反射特性 32
4.2 矽奈米線表面結構及抗反射特性 33
4.2.1 蝕刻後之矽奈米線基板表面比較 33
4.2.2 矽奈米線之表面結構 33
4.2.3 無電鍍金屬沉積技術之蝕刻比例 35
4.2.4 矽奈米線之抗反射特性 36
4.3 等效漸進折射率 37
4.4 矽奈米結構擴散後轉換效率比較 41
4.4.1 矽基板 41
4.4.2 矽奈米尖錐 43
4.4.3 矽奈米線 45
4.4.4 轉換效率之比較 48
第五章 結論 52
第六章 參考文獻 53

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