近年來，因為鈣鈦礦太陽能電池的效率飛速提升，因此鈣鈦礦被視為最有潛力的太陽能電池材料之一。除了效率比肩主流的多晶矽太陽能電池，可溶液製程也是其最大的優勢，因為溶液製程在製備上可以大幅的降低成本，使得鈣鈦礦太陽能電池更符合商業化的需求。但目前鈣鈦礦太陽能電池在大面積與連續生產方面仍然缺乏取得高品質薄膜的製程方法，並且在穩定性方面表現依然不佳。 是故，本實驗透過超音波噴塗法來製備大面積的鈣鈦礦前驅液濕膜，並使用真空萃取技術將濕膜中多餘的溶劑萃取出來，使得結晶成核與退火長晶的過程分開，再於前驅液中加入MACl（methylammonium chloride）使得鈣鈦礦薄膜的長晶時間得以延長，而得到光滑緻密的薄膜。在製程優化後，再經由添加添加劑的方式來提升薄膜的品質與穩定性，這邊我們選擇的添加劑是離子液體BMIMBF4 (1-butyl-3-methylimidazolium tetrafluoroborate)。最後我們得到了最高的光電轉換效率17.26%，並且從太陽能電池特性曲線得到開路電壓0.99 V、短路電流密度22.19 mA cm-2以及填充因子79.39%。這次的實驗很好的提升了大面積生產下的薄膜品質與穩定性，並且增加了鈣鈦礦太陽能電池商業化的可能性。;Metal halide perovskite solar cell have attracted great interest in these years due to its high efficiency and solution process. Now, research focus shifts onto issue related to commercialization. Scalable deposition methods and the stability of device become the most important point to manufacture large-area devices. However, scalable deposition methods usually suffer from non-continuous and non-uniform film, the defect in the film also harm the device stability. In this work, ultrasonic spray-coating method is used to fabricate CH3NH3PbI3 perovskite active layer. The perovskite precursor is optimized with different concentration of methylammonium chloride (MACl) and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4). In the process, the deposited wet film is treated with vacuum-extraction method to extract redundant solvent, at the same time, MACl will interact with lead iodide (PbI2) and methylammonium iodide (MAI) to form a stable and uniform intermediate-state thin film. Then put the substrate on the hot plate, the slowly volatilization of MACl will retard the crystal growth, meanwhile, BMIMBF4 can passivate the defects at surface and grain boundary, finally, we will get a high quality perovskite thin film. The champion device with a power conservation efficiency of 17.26% has been achieved, and show fill factor up to 79%. This study demonstrate the importance of precrystallization for scalable spray-coating technique to achieve good reproducibility, and significantly improve the stability by BMIMBF4.
