使用具粗糙表面結構的氧化鋅摻鎵薄膜作為 矽薄膜太陽能電池前電極之研究

Abstract

One of the essential applications of transparent conductive oxides is as front electrodes for superstrate silicon thin-film solar cells. Textured TCO thin films can improve absorption of sunlight for an a-Si:H absorber during a single optical path. In this study, we have modify texture of GZO by two ways. The first method is etching GZO deposition by an atmospheric pressure plasma enhance chemical vapor deposition(APPECVD). Etching surface by HCl can increase the internal reflection of thin film silicon solar cell. The GZO etching has the lowest resistivity at 1.77× 10−3 Ω cm, and reaches a maximum cell efficiency of 2.87%. The second way for modify texture of GZO is bilayer GZO/SiOx thin films prepared using APPECVD technique and dc magnetron sputtering. The silicon subdioxidenano-film plays an important role in controlling the haze value of subsequent deposited GZO thin films. The GZO/SiOx (90 sccm) double layer sample has the highest haze value (22.30%), the lowest resistivity (8.98× 10−4 Ω cm), and reaches a maximum cell efficiency of 6.85%. We use the GZO/SiOx double layer for deposit the micromorph tandem cell. The maximum of micromorph tandem cell efficiency has 8.42%

透明導電薄膜的其中一個重要應用為矽薄膜太陽能電池的前電極。粗糙化的透明導電薄膜具有抗反射功能且可使光路徑增長, 故可增加吸收層材料的吸收。本研究使用兩種方式製作具粗糙表面透明導電薄膜。第一種方式使使用大氣電漿沉積系統沉積GZO薄膜, 然後進行稀釋鹽酸的蝕刻。此種方式所製作的GZO最低電阻率為1.77x10-3 Ω, 最佳非晶矽電池效率為2.87%。第二種方式為使用大氣電漿沉積系統沉積 粗糙表面的SiOx緩衝層, 然後使用濺鍍系統沉積GZO薄膜於其上, 製作具粗糙表面的GZO/SiOx雙層結構薄膜。實驗中調整Ar載氣流量以控制SiOx表面粗糙度, 最佳Ar載氣流量為90sccm, 並得到最大的霧度22.3%(at 550nm), 最低的電阻率為8.98x10-4Ωcm 與最佳非晶矽電池效率為6.85%。以此最佳參數再進行非晶矽/微晶矽堆疊的太陽能電池, 得到的最佳效率為8.42%。