title: High performance planar heterojunction perovskite solar cells with fullerene derivatives as the electron transport layer.
abstract: In this study, we report the utilization of solution-processed high electrical conductive [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) combined with solution-processed TiO2 as the electron transport layer (ETL) to overcome extremely low electrical conductivity of solution-processed TiO2 ETL in planar heterojunction (PHJ) perovskite hybrid solar cells (pero-HSCs). Due to the much more preferable electron extraction and transportation of PC61BM at the cathode side, a tremendously boosted short-circuit current density (JSC), fill factor (FF) and enhanced power conversion efficiency (PCE) are observed. To further address the wettability issues of perovskite materials on the top of PC61BM, water-soluble fullerene derivative is applied to modulate the surface of PC61BM. Consequently, further advanced FF with slightly enlarged JSC and open-circuit voltage (VOC) are observed. The resulted PCE is comparable with the meso-superstructured solar cells in which high PCEs can be produced. Our studies certainly provide a simple approach to boost the efficiency of PHJ pero-HSCs.
authors.affiliation: College of Polymer Science and Polymer Engineering, University of Akron , Akron, Ohio 44325, United States.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Du
authors.forename: Tianyu
authors.initials: T
authors.lastname: Meng
authors.forename: Xinfei
authors.initials: X
authors.lastname: Yu
authors.forename: Stephen Z D
authors.initials: SZ
authors.lastname: Cheng
authors.forename: Xiong
authors.initials: X
authors.lastname: Gong
keywords: electrical conductivity; electron transport layer; fullerene derivatives; high performance; high-short circuit current; perovskite solar cells