在本論文中，我們為了能在大氣環境下製備鈣鈦礦太陽能電池元件，選擇以溶劑萃取法來製作電池元件，並以乙酸乙酯以及正庚烷這兩種高安全性且低毒性的萃取溶劑，取代一般溶劑萃取製程所使用的乙醚。希望在維持元件效率的同時也能提高製程的安全性，使鈣鈦礦太陽能電池在未來能有機會以工業大量生產。
然而單純以乙酸乙酯或是正庚烷為萃取溶劑所製作的元件有著嚴重的缺陷，因此我們將乙酸乙酯和正庚烷以一定比例混合做為萃取溶劑，利用萃取過程中溶液過飽和度的差異控制鈣鈦礦的結晶過程與表面形貌；其中以乙酸乙酯：正庚烷體積比1:1.5的混合溶劑做為萃取溶劑表現最為穩定，並且較高比例的正庚烷會使鈣鈦礦主動層的表面形貌變得粗糙，有助於增加鈣鈦礦主動層與電洞傳輸層的接觸面積，提升電洞傳輸速率，使電池元件的電流密度有所增益。
最後，做為對照組之使用乙醚做為萃取溶劑的電池元件表現最佳可達到VOC=1.06V，JSC=20.10mA/cm2，FF=75.41%，PCE=16.12%；而使用乙酸乙酯：正庚烷體積比1:1.5的混合溶劑做為萃取溶劑的電池元件表現最佳為VOC=1.06V，JSC=20.58mA/cm2，FF=73.16%，PCE=15.99%。使用乙酸乙酯與正庚烷的混合溶劑做為萃取溶劑的元件，能夠得到與乙醚萃取的元件相近的表現，且在JSC方面能有所增益。

In this study, we used solvent-solvent extraction to fabricate perovskite solar cells under atmosphere. Moreover, because the traditional extraction solvent diethyl ether is unsafe and toxic, we choose two low-toxic extraction solvent ethyl acetate and n-heptane to replace it. We not only maintained the performance of the cell with different extraction solvent but also improved the safety of the fabrication process. The fabrication process can realize the application of industry in the future.
However, the cells with ethyl acetate or n-heptane as the extraction solvent had serious instability and defects. Therefore, we mixed ethyl acetate and n-heptane as the extraction solvent. We controlled the supersaturation of the solution during the extraction to change the crystallization process and surface morphology of perovskite. We found the mixed solvent of the ratio of ethyl acetate to n-heptane is 1:1.5 having best stability as the extraction solvent. On the other hand, the rough surface morphology rough could increase interface contact between the perovskite layer and the hole transport layer raised the opportunity of transporting holes.
Finally, the cells with diethyl ether as the extraction solvent had open-circuit voltage (VOC) of 1.06V, short-circuit current density (JSC) of 20.10 mA/cm2, fill factor (FF) of 75.41%, and power conversion efficiency (PCE) of 16.12%. In contrast, the cells with the ratio of ethyl acetate to n-heptane is 1:1.5 as the extraction solvent had VOC of 1.06V, JSC of 20.58mA/cm2, FF of 73.16%, and PCE of 15.99%.All in all, the performance of the cells with mixed solvent as extraction solvent was similar to diethyl ether, and an enhancement of JSC was obtained.

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