臺灣博碩士論文加值系統

本研究以低電感天線感應耦合電漿化學氣相沉積(inductively coupled plasma,LIA-ICP-CVD)系統製備p-type、n-type nc-Si:H薄膜，利用電漿探針探討電漿對薄膜沉積的影響，再進行X光繞射儀(XRD)、傅立葉轉換紅外光儀(FTIR)、顯微拉曼光譜儀( Raman )、霍爾效應量測系統( Hall measurement )等分析其薄膜，包括結晶性、Si-H鍵結特性、顯微結構及光電特性分析等，並對薄膜品質進行改善。
從薄膜的顯微組織可以發現，由ICP-CVD所製備出的矽氫薄膜，都會有微小的裂縫產生，使薄膜中的載子遷移率不高，但隨著基板溫度的提升和氣體總流量的降低，都能有效降低這些裂縫的數量，讓薄膜的導電率提升。而藉由二次離子質譜分析，可以知道ICP-CVD對於硼和磷的摻雜是非常有效的，矽氫薄膜中的硼與磷原子的摻雜數量都有到達固溶極限。
成功利用ICP-CVD製作太陽能電池，雖然效率只有1.5%，但從電壓電流曲線中，可以看到p-n二極的整流效應，也代表了摻雜的有效性，而效率偏低則是因為過度的摻雜，使開路電壓與短路電流都很小。

n-type and p-type hydrogenated nanocrystalline silicon (nc-Si: H) thin films were deposited by the LIA-ICP-CVD (inductively coupled plasma CVD) system. Using Langmuir Probe discussed plasma conditions effect on the thin films deposition. The films properties Si-H bond, microstructure, crystallinity and conductivity were characterized using X-Ray Diffractometer and Fourier Transform Infrared Spectroscopy, Raman spectrometry, Hall Effect Measurement System, Which enhance the quality of thin films.
From the microstructure of the films, it has been found that a small cracks in the nc-Si:H films prepared by ICP-CVD, thus the carrier mobility in the film is low, but the cracks are decreases with increasing of the substrate temperature and decreasing of the total flow rate. As a result, the conductivity get increases. By SIMS analysis, it has been known that ICP-CVD is very effective for the doping of boron and phosphorus, for the amount of doping in the nc-Si:H films have reached at the solution limit.
The Heterojunction with Intrinsic Thin-layer (HIT) solar cells are successfully prepared by ICP-CVD although the efficiency is 1.5%, but I-V curve can find the p-n rectifier effect, indicating the effectiveness of doping. The low efficiency is due to excessive doping. Consequently, The VOC and ISC are very small.

指導教授推薦書 i
口試委員會審定書 ii
誌謝 iii
摘要 iv
Abstract v
目　錄 vi
表目錄 ix
圖目錄 x
第一章 緒論 1
1.1前言 1
1.2研究動機 3
第二章 文獻回顧與基本理論 4
2.1太陽能電池原理簡介 4
2.1.1光電轉換原理 4
2.1.2太陽能電池能源轉換效率 7
2.2矽薄膜太陽能電池種類 9
2.2.1 非晶矽(a-Si)薄膜太陽電池 10
2.2.2 光劣化效應 12
2.2.3 矽氫薄膜之矽氫原子鍵 14
2.2.4 奈米晶矽(nc-Si)氫薄膜 15
2.3 矽薄膜摻雜 20
2.4 LIA-ICP CVD 22
第三章 實驗規劃與方法 25
3.1實驗規劃 25
3.1.1實驗設計 25
3.1.2實驗流程 27
3.2 檢測分析儀器 28
3.2.1 蘭摩爾探針 (Langmuir Probe) 28
3.2.2 傅立葉轉換紅外光譜儀 (Fourier Transform Infrared: FTIR) 30
3.2.3 顯微拉曼光譜儀 (Micro-Raman Spectroscopy ) 31
3.2.4 X光繞射儀 (X-Ray Diffractometer) 33
3.2.5 XRR對單層薄膜厚度分析儀 35
3.2.6霍爾效應量測系統 ( Hall Effect Measurement System) 39
3.2.7高解析穿透式電子顯微鏡 ( High Resolution Transmission Electron Microscope HR-TEM ) 41
3.2.8飛行時間二次離子質譜儀 (Time-of-Flight Secondary Ion Mass Spectrometer TOF-SIMS ) 44
第四章 結果與討論 45
4.1 電漿密度與電子溫度 45
4.2 低電漿密度及高電子溫度 51
4.2.1 基板溫度對硼含量之影響 51
4.2.2 退火溫度對載子遷移率之影響 59
4.2.3 改變氣體總流量對載子遷移率之影響 65
4.2.4 改變PH3流量對n-typ 薄膜的影響 71
4.3 高電漿密度及高電子溫度 75
4.3.1 改變工作壓力對薄膜品質之影響 77
4.3.2 改變工RF功率對薄膜品質之影響 81
4.3.3 薄膜品質對導電性的影響 84
4.3.4 太陽能電池試做 86
第五章 結論 88
參考文獻 89

表目錄
表3-1實驗參數變化表 26
表4-1 實驗驗證參數 45
表4-2 溫度變化 51
表4-3 製程參數 59
表4-4 降低氣體種流量 65
表4-5 降低氣體種流量 71
表4-6 D 4條件 75
表4-7 工作壓力之變化 77
表4-8 改變RF功率 81
表4-9 太陽能電池參數 86

 
圖目錄
圖1-1再生能源趨勢 2
圖1-2 美國 NREL 公司統計各類太陽電池種類及最佳效率圖 2
圖2-1 矽的結晶結構圖 5
圖2-2 p、n型半導體示意圖 6
圖2-3 p-n接面示意圖 6
圖2-4太陽能電池電壓電-流特性曲線 8
圖2-5 a-Si:H/ a-Si:H 與 a-Si:H/ u-Si:H 疊層太陽能電池光譜圖 9
圖2-6 a-Si:H生長機制圖 11
圖2-7 a-Si:H生長機制圖 13
圖2-8 Staebler-Wronski 懸鍵產生反應圖 13
圖2-9 矽氫原子鍵結(a)微晶矽與(b)非晶矽原子鍵結 14
圖2-10 (a) 表面擴散型模型 17
圖2-10 (b)蝕刻模型 18
圖2-10 (c)化學退火模型 18
圖2-11功率密度與氫流量對結晶率之影響 19
圖2-12矽氫薄膜的微結構隨著結晶分率變化 19
圖2-13 硼和磷固溶極限 20
圖2-14 矽磷合金相 20
圖2-15硼氫交錯示意圖 21
圖2-16硼在矽和二氧化矽界面析出 21
圖2-17 U型低電感天線線圈 24
圖2-18 LIA-ICP與VHF-CCP 功率與(a)電漿電位(b)電子密度圖 24
圖3-1 本實驗室瓦數、工作壓力、基板溫度、氣體流量比之參數 25
圖3-2理想Langmuir Probe的I-V曲線 29
圖3-3拉曼光譜散射機制 32
圖3-4 X光繞射儀之布拉格繞射定律示意圖 34
圖3-5 Detector scan mode 以θ＝1 o 的低掠角XRD (Glancing incident XRD，GIXRD)量測示意圖 34
圖3-6 (a)X 光反射(XRR)檢測示意圖，(b)單層薄膜 XRR 檢測結果圖，(c)入射 X 光源發生全反射示意圖 37
圖3-7 霍爾效應示意圖 40
圖3-8 van der Pauw量測法之樣品形狀 40
圖3-9量測RA與RB的接線示意圖 41
圖3-10量測RC與RD的接線示意圖 41
圖3-11為飛行時間二次離子質譜儀 44
圖4-1三個不同的電漿狀態 47
圖4-2不同電漿狀態的薄膜沉積速率與薄膜導電性 47
圖4-3不同電漿狀態的載子濃度和載子遷移率 48
圖4-4不同電漿狀態的薄膜R值與總氫含量 48
圖4-5不同電漿狀態的薄膜結晶性與拉曼偏移 49
圖4-6不同電漿狀態的XRD圖 49
圖4-7不同電漿狀態的顯微組織(a)第一階段(b)第二階段(c)第三階段 50
圖4-8基板溫度對薄膜沉積速率與薄膜密度之影響 53
圖4-9不同基板溫度之XRD圖 53
圖4-10基板溫度對薄膜結晶率與拉曼偏移之影響 54
圖4-11基板溫度對薄膜導電性、載子濃度、載子遷移率之影響 54
圖4-12 (a)到(d)為不同基板溫度的TEM top-view組織 56
圖4-13不同基板溫度的硼原子量與有效載子數 57
圖4-14不同基板溫度的薄膜R值與總氫含量 57
圖4-15不同基板溫度的XPS分析 58
圖4-16不同退火溫度之薄膜R值與總氫含量 61
圖4-17不同退火溫度之薄膜導電性、載子遷移率、載子濃度 61
圖4-18不同退火溫度之薄膜結晶率和拉曼偏移 62
圖4-19不同退火溫度之XRD與晶粒大小 62
圖4-20 (a)到(d)為退火前後的上視與側視圖 64
圖4-21退火前後之縱深分析 65
圖4-22氣體總流量對薄膜沉積速率與薄膜密度之影響 66
圖4-23氣體總流量對薄膜R值與氫含量之影響 67
圖4-24氣體總流量對薄膜結晶率與拉曼偏移之影響 67
圖4-25氣體總流量之XRD圖與晶粒大小 68
圖4-26氣體總流量對導電性、載子濃度、載子遷移率之影響 68
圖4-27不同總氣體流量的TEM上視圖 70
圖4-28 PH3氣體流量對薄膜沉積速率與薄膜密度之影響 72
圖4-29 PH3氣體流量對薄膜R值與氫含量之影響 73
圖4-30 PH3氣體流量對薄膜結晶率與拉曼偏移之影響 73
圖4-31 PH3氣體流量對薄膜導電性、載子濃度、載子遷移率、原子數量之影響 74
圖4-32 n、p型薄膜退火前後電性比較 74
圖4-33不同工作壓力的電漿密度與電子溫度 76
圖4-34不同功率的電漿密度與電子溫度 76
圖4-35不同工作壓力的薄膜沉積速率和薄膜密度 78
圖4-36不同工作壓力的薄膜結晶率和拉曼偏移 78
圖4-37不同工作壓力的XRD圖 79
圖4-38不同工作壓力對薄膜導電性、載子濃度、載子遷移率之影響 79
圖4-39不同工作壓力的TEM上視圖 80
圖4-40不同功率的薄膜沉積速率與薄膜密度圖 82
圖4-41不同功率的XRD結構圖 82
圖4-42不同功率的薄膜結晶率和拉曼偏移 83
圖4-43不同功率對薄膜導電性、載子濃度、載子遷移率之影響 83
圖4-44為所有實驗參數之導電與模擬值 85
圖4-45 (a)為p-layer nc-Si結構(b)為a-Si結構 87

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