title: Isomer-Pure Bis-PCBM-Assisted Crystal Engineering of Perovskite Solar Cells Showing Excellent Efficiency and Stability.
abstract: A fullerene derivative (α-bis-PCBM) is purified from an as-produced bis-phenyl-C61-butyric acid methyl ester (bis-[60]PCBM) isomer mixture by preparative peak-recycling, high-performance liquid chromatography, and is employed as a templating agent for solution processing of metal halide perovskite films via an antisolvent method. The resulting α-bis-PCBM-containing perovskite solar cells achieve better stability, efficiency, and reproducibility when compared with analogous cells containing PCBM. α-bis-PCBM fills the vacancies and grain boundaries of the perovskite film, enhancing the crystallization of perovskites and addressing the issue of slow electron extraction. In addition, α-bis-PCBM resists the ingression of moisture and passivates voids or pinholes generated in the hole-transporting layer. As a result, a power conversion efficiency (PCE) of 20.8% is obtained, compared with 19.9% by PCBM, and is accompanied by excellent stability under heat and simulated sunlight. The PCE of unsealed devices dropped by less than 10% in ambient air (40% RH) after 44 d at 65 °C, and by 4% after 600 h under continuous full-sun illumination and maximum power point tracking, respectively.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China.|Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.|Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 300072, Tianjin, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London, E1 4NS, UK.
authors.forename: Wenda
authors.initials: W
authors.lastname: Shi
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Jingshan
authors.initials: J
authors.lastname: Luo
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.|Max Planck Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart, 70569, Germany.
authors.forename: Norman
authors.initials: N
authors.lastname: Pellet
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Chenyi
authors.initials: C
authors.lastname: Yi
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Xiong
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China.|Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 300072, Tianjin, China.|School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London, E1 4NS, UK.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhao
authors.affiliation: School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London, E1 4NS, UK.
authors.forename: T John S
authors.initials: TJS
authors.lastname: Dennis
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China.|Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 300072, Tianjin, China.
authors.forename: Xianggao
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China.|Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 300072, Tianjin, China.
authors.forename: Shirong
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China.|Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 300072, Tianjin, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Shaik Mohammed
authors.initials: SM
authors.lastname: Zakeeruddin
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Dongqin
authors.initials: D
authors.lastname: Bi
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
keywords: bis-PCBM; perovskites; solar cells; stabilities