研究生: |
曾文昭 Tseng, Wen-Chao |
---|---|
論文名稱: |
在低溫下利用電漿輔助化學氣相沉積成長非晶碳化矽薄膜與光伏元件之研究 Low Temperature Growth of a-SiC:H Thin Film by Plasma Enhanced Chemical Vapor Deposition for Photovoltaic Application |
指導教授: |
柳克強
Leou, Keh-Chyang |
口試委員: |
吳永俊
王敏全 |
學位類別: |
碩士 Master |
系所名稱: |
原子科學院 - 工程與系統科學系 Department of Engineering and System Science |
論文出版年: | 2012 |
畢業學年度: | 100 |
語文別: | 中文 |
論文頁數: | 140 |
中文關鍵詞: | 電漿輔助化學氣相沉積 、光譜 、非晶碳化矽 |
相關次數: | 點閱:2 下載:0 |
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近年來能源議題逐漸受到關注,而發展中的太陽能發電不但供應了源源不絕的能量且不會對地球造成汙染,使各界認為太陽能源或許能是未來的替代能源。而市面上最廣泛應用的是矽晶太陽電池,可分為兩大類: 1.塊材2.薄膜。後者矽消耗量小,相較之下可以降低成本,且沉積溫度在較低溫就可進行,可以減少浪費。一般矽薄膜太陽電池是利用非晶矽薄膜製作而成,而如果在製程氣體上加入甲烷或乙烷提供碳形成(amorphous silicon carbide a-SiC:H)薄膜,研究上顯示會形成高能隙太陽電池,在發光二極體、智慧節能窗等皆有相關應用。
a-SiCx:H薄膜中,Si-C鍵比例增高時,薄膜整體晶格無序增加使電池的光電特性下降。而如果在較低溫(150 ℃)下沉積,光暗電導還會再下降。由於太陽電池中可撓式基板逐漸受到矚目,在低溫下製程並有較高品質薄膜則顯得格外重要。因此本研究主要著重在低製程溫度(150 ℃)沉積a-SiC:H薄膜,並結合材料特性、電漿特性和光譜儀分析(Optical Emission Spectroscopy,OES)之製程參數變化尋求關聯性,獲得高光學能隙與高光敏性吸收層之薄膜,同時結合N、P層形成PIN太陽電池元件。
本實驗方法是利用27.12 MHz 的Plasma Enhanced Chemical Vapor Deposition (PECVD)沉積,同時藉由OES量測並記錄電漿中粒子的放射光強度,之後分析粒子的相對強度(如Hβ/Hα、CH/SiH*等OES-ratio)建立電漿光譜。因薄膜在低溫條件下材料品質會不太穩定,因此可以藉由OES提供一即時偵測電漿腔體穩定性外,也可利用放射光強度相對變化預測光學能隙在隨參數變化時之趨勢。研究發現,電漿放射光強度比(CH/SiH*)與薄膜光學能隙(Eg)具有相同的趨勢。所沉積的本質層薄膜具有高能隙特性,結合P、N層形成PIN單一接面太陽電池,具則有高穿透率、高開路電壓之特性,已接近電致變色片的需求。而元件在照光下的電壓電流曲線圖呈S曲線,推測原因為能階不匹配所導致。
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