應用於多接面薄膜太陽能電池之非晶矽氧電池之開發與研究

Abstract

本研究利用射頻電漿輔助化學氣相沉積系統來沉積非晶矽氧電池，並應用於多接面薄膜太陽能電池。為了改善非晶矽氧電池之效率，吸收層與摻雜層的薄膜特性皆需要改善與優化。首先，我們研究不同製程參數對p型非晶矽氧薄膜特性的影響，並找出適合運用於非晶矽氧電池的較佳參數，此較佳參數所沉積的p型非晶矽氧薄膜特性為能隙2.01 eV，電導為2.5×10-8 S/cm。接著，比較p型非晶矽氧薄膜或p型非晶碳化矽薄膜為窗口層對非晶矽氧電池效能的影響。利用p型非晶矽氧薄膜可得到較高開路電壓使整體電池轉換效率提升。之後，研究不同n型參雜層對非晶矽氧電池特性的影響。使用n型微晶矽氧薄膜可得到較佳的短路電流；使用n型微晶矽薄膜可得到較佳的轉換效率。改善過後的非晶矽氧電池的效率可達5.38%，其中開路電壓為880 mV，短路電流為 9.63 mA/cm2，填充因子為70.8%。最後，將改善過後的非晶矽氧電池搭配非晶矽鍺電池及微晶矽電池，做成非晶矽氧/非晶矽鍺雙接面電池與非晶矽氧/非晶矽鍺/微晶矽三接面電池。本研究中，三接面太陽能電池的效率為9.05%，其中開路電壓為2.02 V，短路電流為6.13 mA/cm2，填充因子為73.2%。

In this study, plasma-enhanced chemical vapor deposition (PECVD) was used to deposit hydrogenated amorphous silicon oxide (a-SiOX:H) cell for multi-junction thin-film solar cell application. In order to improve the cell performance of a-SiOX:H cell, absorber and doped-layer in the cell was optimized. First, we studied the influence of deposition condition on the opto-electrical properties of a-SiOX:H p-type layer and applied it on a-SiOX:H cell. Second, cells with hydrogenated amorphous silicon carbide (a-SiCX:H) and a-SiOX:H p-type layer were compared. The cell with a-SiOX:H p-type layer had higher cell efficiency due to the increase in VOC. Third, we studied the effect of different n-type layer on the performance of a-SiOX:H cell. Hydrogenated amorphous silicon (a-Si:H), hydrogenated microcrystalline silicon (μc-Si:H), hydrogenated microcrystalline silicon oxide (μc-SiOX:H) n-type layer were employed in cells. The cell with μc-Si:H n-layer had better performance among these cells. Finally, we applied the optimized a-SiOX:H cell to prepare a-SiOX:H/a-Si1-XGeX:H tandem and a-SiOX:H/a-Si1-XGeX:H/μc-Si:H triple-junction solar cells. The cell efficiency of triple-junction solar cell was 9.05% with VOC=2.02 V, JSC=6.13 mA/cm2 and F.F.=73.2%.