我們設計並合成了一系列以Carbazole為核心主體的新型(A-π-D-π-A)分子SY1-SY4，以它們作為電洞傳輸材料(Hole Transporting Material, HTM)或界面層來應用在n-i-p或p-i-n結構的鈣鈦礦太陽能電池。在SY系列中分別以ethyl cyanoacetate與2-cyano-N-hexylacetamide來作為末端受體基團，它們具有良好的熱穩定性與合適的能階，但在溶解性方面表現較不理想。以SY系列作為HTM應用在n-i-p鈣鈦礦太陽能電池中，其中SY1表現出13.9%最高的光電轉換效率(power conversion efficiency, PCE)。而在p-i-n鈣鈦礦太陽能電池中，SY2作為無摻雜劑的空穴傳輸材料表現出12.1%最高的PCE，這與作為標準物的PEDOT：PSS(12.7%)非常接近。經過一系列的形態學研究，SY系列表現出良好的平整性、疏水性並獲得品質更高的鈣鈦礦層，而其中特別的是具有醯胺基團的SY2和SY4相較於具有酯類基團的SY1和SY3表現出更大的鈣鈦礦晶粒尺寸(1-1.2 μm)。我們試著用SY系列作為界面層來修飾作為HTM的NiOx，在未修飾前NiOx作為HTM得到17.6%的光電轉換效率，而在經過SY系列修飾後，不論是平整性、疏水性還是鈣鈦礦的晶粒尺寸皆有更好的表現，其中SY2表現出18.3%最高的PCE。 We demonstrated a novel carbazole-based (A-π-D-π-A) type structures of SY1-SY4 with two kinds of acceptor, ethyl cyanoacetate and 2-cyano-N-hexylacetamide. We use SY1−SY4 not only as hole transporting materials (HTMs) but also interfacial layer for application in n-i-p or p-i-n perovskite solar cells. We demonstrated SY1 as the hole transporting material achieved a power conversion efficiency (PCE) of 13.9% in n−i−p type device of perovskite solar cells. And the perovskite solar cells with inverted dopant-free p−i−n type device structure by using SY2 as the hole transporting material achieved a power conversion efficiency (PCE) of 12.1%, which is similar to PEDOT:PSS as HTMs (12.7%). We observed the morphology study revealed that the film of SY1−SY4 was smooth and hydrophobic. Interestingly, SY2 and SY4 with the amide group may enhance the grain size of the perovskite. Therefore, we try to modify NiOx HTM by using SY2 as the interfacial layer achieved a power conversion efficiency (PCE) of 18.3% in perovskite solar cells, compared to bare NiOx as HTMs (16.2%).
