本實驗探討不同鎘鹽類材料所鍍製之硫化鎘(CdS)緩衝層薄膜特性，及後續鎘離子擴散處理參數對軟性CIGS太陽電池元件效率影響之研究，並以軟體模擬探討鎘離子擴散量與深度對CIGS太陽電池元件特性與實驗比較。在使用化學水浴沉積法(Chemical bath deposion, CBD)鍍製n-CdS緩衝層時，溶液中的鎘(Cd)離子會擴散進入CIGS薄膜表面，形成n-CIGS:Cd，產生電性反轉，此型態的n-CdS/n-CIGS:Cd/p-CIGS(CIGSS)介面可調控CIGS太陽電池元件之空乏區寬度、內建電場、載子濃度等特性，有助於優化CIGS元件的開路電壓及短路電流，提升元件效率。因此本實驗首先將CIGS樣品浸泡於硫酸鎘溶液，藉由調整溶液中的氨水濃度、浸泡溫度、時間等參數，分析Cd離子在CIGS薄膜表面的擴散量及深度(Cd ion soaking treatment)；接著使用CBD法製作CdS薄膜，選用不同鎘鹽類材料、硫脲及氨水進行調配，藉由溶液pH值調整、鍍膜時間及溫度，控制CdS結晶顆粒大小，並製作出均勻性佳且透光性良好的CdS薄膜，其厚度約60nm，鍍製於已擴散Cd/S離子的CIGS樣品上，最後製作成CIGS太陽電池元件，得到最佳效率6.36%，VOC為0.503 V，JSC為32 mA/cm2，FF為39.1%。

In this study, it was discussed the effect of CdS films for different Cd source and Cd ion soaking treatment on the CIGS flexible solar cells. In addition, it was analyzed by the effect of Cd diffusion depth on the CIGS solar cells by simulation, comparing with experimental. During n-CdS films deposited by chemical bath deposition (CBD), Cd ion diffused into CIGS surface formed n-CIGS:Cd, resulting n-CdS/n-CIGS:Cd/p-CIGS(CIGSS) structure. This structure was a buried homo- junction, and it could widen the space charge region in CIGS solar cell, resulting in open circuit voltage (VOC) and short circuit current density (JSC) increased. Therefore, in the experimental, the CIGS films would soak into Cd ion solution with various NH3 concentrations, soaking temperature and soaking time. Then, CdS films deposited by different Cd source, and the thickness of CdS films were 60 nm. Finally, CIGS flexible solar cells were fabricated. The CIGS flexible solar cells performance was that the efficiency was 6.36%, VOC was 0.50 V, JSC was 32 mA/cm2, FF was 39.1%, improved by Cd ion soaking treatment on CIGS flexible solar cells.

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