臺灣博碩士論文加值系統

本論文主要將討論單晶矽奈米線陣列於光伏原件上之應用，矽奈米線陣列所形成之表面具有良好抗反射率，可以有效提升太陽光之吸收。製作矽奈米線陣列的方式為無電鍍蝕刻法，系將一p-type(100)之矽基板置入氫氟酸與銷酸銀的混合蝕刻液中，當溶液中之氟離子與矽基板接觸後，矽即被解離成矽離子並放出一顆電子。此電子與溶液中之銀離子結合並形成顆粒於矽基板表面，被銀顆粒覆蓋住的區域能夠受到保護不被氟離子繼續蝕刻。最後，因為各晶面具有不同之蝕刻速率，(100)之矽基板表面會形成垂直於基板之奈米線陣列。
製作太陽能電池之方式，系將一P2O5之溶液利用spin-on之方式旋轉塗佈於矽奈米陣列上，再利用快速熱退火(Rapid Thermal Annealing, RTA) 的方式將磷擴散入矽基板中，形成PN接面以有效分離電子電洞對，產生光電流。將討論快速熱退火在不同之參數下對於太陽能電池效率的影響。此外，無電鍍蝕刻法所製成之矽奈米線，其表面具有大量斷鍵所形成之缺陷，大量缺陷將會使得光電流減少。故利用氫氣做表面鈍化處理以提高太陽能電池效率。此外，亦在矽奈米線表面利用二次磷擴散製程成形heavily doped region，以期使電洞離開表面減少被複合機會而提升電池效率。雖然矽奈米線結構具有在可見光波段可低至1%以下的反射率，但矽奈米線表面過多的缺陷使得最中只獲得8.52%的最佳轉換效率。
關於光觸媒元件的製作，係將二氧化鈦薄膜利用ALD法鍍於矽奈米線陣列上，利用恆電位儀量測其電化學性質。在二氧化鈦/n型或p型矽異質結構中，於未外加偏壓的情形中由實驗結果顯示，在照光下樣品表面具有自行產生氧氣的能力；在二氧化鈦鍍於矽奈米陣列太陽能電池上的實驗中，由實驗結果顯示，照光下樣品表面具有自行產生氫氣的能力。

In this study, large area silicon nanowire (SiNW)arrays were applied on photovoltaic device. This structure had excellent anti-reflection ability and improved the absorption of solar energy. The fabrication of SiNW was used by “electroless etching” which was when (100) c-Si was immersed in the solution containing silver nitrate and hydrofluoric acid. Si was etched by fluoric ion and released electrons to combine with silver ion to form Ag particles. Ag particles recovered the surface of sample and the region below Ag particles was protected by Ag. Finally, because of the different etching velocity on each crystal surface we got large area well-aligned silicon nanowire arrays.
In this study, SiNW arrays were applied on solar cell. The formation of PN junction was a p-type SiNW subtracts annealing by rapid thermal annealing with spin-on phosphorous source. Although SiNW solar cell had good anti-reflection ability but the large surface defects on SiNW confined the highest conversion efficiency only to 8.52% .
At last, the Titanium dioxide film was deposited on SiNW by ALD and used potentiostat to measure chemical property. For TiO2/SiNW hetero-junction, under AM 1.5G light we observed that oxygen flowed out from sample surface; for TiO2/SiNW solar cell structure ,we found hydrogen gas flowing out from surface on AM 1.5G.

口試委員會審定書 I
誌謝 II
中文摘要 III
英文摘要 IV
目錄 VI
第一章 緒論 1
1.1 前言 1
1.2 本文研究概要 1
第二章 基本原理介紹 3
2.1 基本介紹 3
2.1.1太陽光譜 3
2.1.2光伏電池元件 4
2.1.3半導體材料的選擇 5
2.1.4 矽的光學基本性質 5
2.2 二極體原理 8
2.2.1 PN接面 8
2.2.2 空乏區電位 10
2.2.3 空乏區電場強度與空乏區寬度 11
2.2.4理想二極體方程式 13
2.2.5空乏區複合產生電流 16
2.3太陽能電池工作原理 19
2.3.1太陽能電池理想等效電路 19
2.3.2影響太陽能電池效率之因素 22
2.4 二氧化鈦薄膜與光水解基本原理 29
第三章 實驗流程與儀器操作簡介 31
3.1矽奈米線的製作流程與表面結構的相關量測 31
3.1.1 樣品清洗 33
3.1.2 蝕刻液的配製 34
3.1.3 晶片的蝕刻 34
3.1.4 樣品表面形貌的觀測 36
3.1.5 矽奈米線陣列之反射率測量 36
3.2 太陽能電池製作流程 37
3.2.1 PN接面的製作 37
3.2.2 晶片邊緣絕緣處理 38
3.2.3 正背電極的製作 39
3.3 太陽能電池效率量測與相關測量 42
3.4矽-二氧化鈦異質結構量測 44
3.4.1樣品的制備 45
3.4.2樣品電化學之電壓電流特性量測 45
第四章 實驗結果與討論 48
4.1 矽奈米線的結構與抗反射率 48
4.1.1 矽奈米線結構 48
4.1.2 抗反射率之量測 53
4.2太陽能電池製作與量測結果 56
4.3 TIO2與SI 異質結構之實驗結果與討論 75
結論 86
參考文獻 87

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