摻雜鐵離子之銅銦鎵硒太陽電池製備與特性分析

Preparation and Characterization of Iron-ion Doped Copper Indium Gallium Diselenide Solar Cells

邱冠霖(Guan-Lin Chiu)

指導教授 ： 呂宗昕

國立臺灣大學/工學院/化學工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201602350

摘要

本研究以非真空的旋轉塗佈法，在可撓式不鏽鋼基板上製備銅銦鎵硒(CIGS)
薄膜，並且探討鐵離子對銅銦鎵硒薄膜與太陽能電池的影響。第一部分探討不同鐵離子摻雜比例對銅銦鎵硒薄膜與太陽電池之影響。當鐵離子對銦、鎵離子的莫耳比增加時，轉換效率大幅降低。由於鐵離子的摻雜，使銅銦鎵硒晶粒變為較小且不規則的尖銳形狀，造成晶界大幅增加，形成許多分流路徑，使電子和電洞在此發生再結合，因此降低轉換效率。
第二部分探討以不同溫度硒化，對摻雜鐵離子的銅銦鎵硒薄膜與太陽電池之影響，並以未摻雜鐵離子的銅銦鎵硒薄膜與太陽電池做為比較。當硒化溫度提升至550°C，未摻鐵以及摻雜鐵離子的銅銦鎵硒太陽電池轉換效率最佳。轉換效率的提升是由於薄膜的晶粒大小以及緻密性的改善。而將硒化溫度提升至575°C時，基板鐵離子擴散至吸收層，使薄膜變為不規則的尖銳型態，使電子和電洞容易於晶界發生再結合，因此降低轉換效率。

關鍵字

銅銦鎵硒 ； 鐵離子 ； 不鏽鋼基板 ； 旋轉塗佈法 ； 非真空製程

並列摘要

Cu(In,Ga)Se2 thin films were prepared on flexible stainless steel substrates via the non-vacuum spin-coating process in this study. The influences of iron ions on the Cu(In,Ga)Se2 thin films and solar cells were investigated. In the first part, the effects of different ratios of iron ions doping on the Cu(In,Ga)Se2 thin films and solar cells were studied. The conversion efficiency of the Cu(In,Ga)Se2 solar cells was significantly decreased when the molar ratio of iron ions to indium and gallium ions was increased.
The decrease in the conversion efficiency was due to the iron doping, which made the grains of the Cu(In,Ga)Se2 thin films become smaller. The morphology of the Cu(In,Ga)Se2 thin films became sharp and irregular. The change in morphology increased the amounts of grain boundaries and formed additional shunt paths, which led to electron-hole recombination.
In the second part, the effects of selenization temperatures on the iron-doped Cu(In,Ga)Se2 thin films and solar cells were investigated. The undoped Cu(In,Ga)Se2 thin films and solar cells were fabricated as the references. The highest conversion efficiency of the doped and undoped Cu(In,Ga)Se2 solar cells was reached when the selenization temperature was increased to 550°C. The increase in conversion efficiency was attributed to the large grain sizes and densification of the films.
As the selenization temperature further increased to 575°C, the iron ions in the substrates diffused into the absorber layers. The morphology of the Cu(In,Ga)Se2 thin films become sharp and irregular. The change in morphology led to high probability of electron-hole recombination. Therefore, the conversion efficiency of the doped and undoped Cu(In,Ga)Se2 solar cells decreased.

並列關鍵字

Cu(In,Ga)Se2 ； iron ions ； stainless steel substrates ； spin-coating process ； non-vacuum process

參考文獻

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