在本論文中，我們利用氫和氧電漿處理透明導電電極與低壓沉積製備非晶本質矽鍺膜來提升非晶矽基薄膜太陽能電池的特性。首先，因串聯電阻對非晶矽基薄膜太陽能電池的特性有相當大的影響，利用氫和氧電漿可去除透明導電電極表面之碳氫化合物污染,提高其功函數，並降低其與非晶薄膜之間的蕭特基位障，實驗結果顯示先用氫氣電漿(100 W, 0.4 torr, 基板溫度=25℃)處理5分鐘再用氧氣電漿(55 W, 0.15 torr, 基板溫度=25℃)處理5分鐘可明顯提昇元件特性。此外，我們在低壓沉積非晶本質矽鍺吸光層用以減少薄膜中的Si=H2 鍵結，進而提升非晶矽基薄膜太陽能電池的特性，所製作出的梯度非晶矽基薄膜太陽能電池，其轉換效率可達到百分之 3.63。 In this thesis, the H2/O2-plasma treatments on transparent indium-tin-oxide (ITO) electrode and deposition of i-a-SiGe:H absorption layer at low pressure have been used to improve the performance of amorphous Si-alloy based thin-film solar cells. Firstly, since that the series resistance between the ITO electrode and amorphous layer plays an important role in the performance of a solar cell, the in-situ plasma treatments was employed to improve the contact and it was found that the performance of a p-i-n a-Si:H thin-film solar cell could be enhanced with the H2-plasma (100 W, 0.4 torr, 25 ℃ and 5 min.) and then O2-plasma (55 W, 0.15 torr, 25 ℃ and 5min.) treatments on ITO electrode. This was due to the combination of H2- and O2-plasma treatments could remove the hydrocarbon compounds and increase the work function of ITO electrode. Hence, the Schottky barrier height between the ITO and amorphous layer could be lowered. In addition, the i-a-SiGe:H absorption layer was deposited at a lower pressure of around 0.25 torr with a plasma-enhanced chemical vapor deposition system, to reduce the amount of Si=H2 bonds in the film and hence improve the performance of graded ITO/p-SiC:H/buffer layer (i-a-SiC:H)/i-a-Si:H/interface layer/i-a-SiGe:H/n-a-Si:H/Al solar cell. In this study, the highest obtainable conversion efficiency of this graded solar cell was 3.63 %.
