title: Improved Performance and Stability of Inverted Planar Perovskite Solar Cells Using Fulleropyrrolidine Layers.
abstract: Inverted planar structure perovskite solar cells (PSCs), due to their low-temperature precessing and lack of hysteretic problems, are attracting increased attention by researchers around the world. Fullerene derivatives are the most widely used electron transport materials (ETMs) in inverted planar perovskite solar cells, especially [6,6]-phenyl-C61-butyric acid methylester (PC61BM), which exhibits very good performance. However, to the best of our knowledge, the influence of adducts on fullerene-based PSCs performance has not been fully explored to date. In this work, two fullerene derivatives, 2,5-(dimethyl ester) C60fulleropyrrolidine (DMEC60) and the analogous C70derivative (DMEC70), were synthesized in high yield via a 1,3-dipolar cycloaddition reaction at room temperature and incorporated into CH3NH3PbI3perovskite solar cells as electron transport materials. Possibly because the attached pyrrolidine ester groups are able to coordinate with the perovskite layer, the devices based on DMEC60and DMEC70achieved power conversion efficiencies (PCE) of 15.2% and 16.4%, respectively. Not only were both devices' efficiencies higher than those based on PC61BM and PC71BM, but their stabilities were also higher than those for PCBM-based devices. The results suggest that DMEC60and DMEC70are better alternatives than PC61BM and PC71BM for the ETMs in PSCs.
authors.affiliation: Department of Chemistry, University of Texas at El Paso , 500 West University Avenue, El Paso, Texas 79968, United States.
authors.forename: Chengbo
authors.initials: C
authors.lastname: Tian
authors.affiliation: Department of Chemistry, University of Texas at El Paso , 500 West University Avenue, El Paso, Texas 79968, United States.
authors.forename: Edison
authors.initials: E
authors.lastname: Castro
authors.affiliation: iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, China.
authors.forename: Tan
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Chemistry, University of Texas at El Paso , 500 West University Avenue, El Paso, Texas 79968, United States.
authors.forename: German
authors.initials: G
authors.lastname: Betancourt-Solis
authors.affiliation: Department of Chemistry, University of Texas at El Paso , 500 West University Avenue, El Paso, Texas 79968, United States.
authors.forename: Gloria
authors.initials: G
authors.lastname: Rodriguez
authors.affiliation: Department of Chemistry, University of Texas at El Paso , 500 West University Avenue, El Paso, Texas 79968, United States.
authors.forename: Luis
authors.initials: L
authors.lastname: Echegoyen
keywords: coordination; electron transport layer; fullerene derivatives; interfacial interactions; perovskite solar cells