(Invited) Efficient Fullerene-Based Electron Acceptors for Planar Perovskite Solar Cells

Tuesday, 30 May 2017: 08:40
Churchill A2 (Hilton New Orleans Riverside)
S. Y. Xie (Department of Chemistry, Xiamen University)
Discovery of organic-inorganic hybrid perovskites ignites the dream of next-generation solar cells fabricated by low-cost solution processing. To date, fullerene derivative [6,6]-phenyl-C61- butyric acid methyl ester (PC61BM), is the most prevalently used electron transport material (ETM) for high efficiency inverted planar heterojunction (PHJ) perovskite solar cells. Compared with PC61BM, pristine fullerenes, such as C60 and C70, have shown superiority of higher electron mobility and much lower costs. Due to the poor solubility and strong tendency to crystallize for pristine fullerenes in solution process, it is still a challenge to deposit compact and continuous film of pristine fullerenes for inverted PHJ perovskite solar cells by solution processing. Herein, solution processed pristine fullerenes (C60 and C70) were used as ETMs to replace PC61BM in inverted PHJ perovskite solar cells with high performance and enhanced stability. Power conversion efficiency of 14.04% was obtained by using mixture of C60 and C70 as ETM, which is comparable to that of PC61BM-involving device (13.74%). We demonstrated that the strong tendency of pristine fullerenes to crystallize on solvent removal can be largely mitigated by mixing different kinds of pristine fullerenes, with implication about a promising future of pristine fullerenes as ETMs for high performance perovskite solar cells.