title: Fast Crystallization and Improved Stability of Perovskite Solar Cells with Zn2SnO4 Electron Transporting Layer: Interface Matters.
abstract: Here we report that mesoporous ternary oxide Zn2SnO4 can significantly promotes the crystallization of hybrid perovskite layers and serves as an efficient electron transporting material in perovskite solar cells. Such devices exhibit an energy conversion efficiency of 13.34%, which is even higher than that achieved with the commonly used TiO2 in the similar experimental conditions (9.1%). Simple one-step spin coating of CH3NH3PbI3-xClx on Zn2SnO4 is found to lead to rapidly crystallized bilayer perovskite structure without any solvent engineering. Furthermore, ultrafast transient absorption measurement reveals efficient charge transfer at the Zn2SnO4/perovskite interface. Most importantly, solar cells with Zn2SnO4 as the electron-transporting material exhibit negligible electrical hysteresis and exceptionally high stability without encapsulation for over one month. Besides underscoring Zn2SnO4 as a highly promising electron transporting material for perovskite solar cells, our results demonstrate the significant role of interfaces on improving the perovskite crystallization and photovoltaic performance.
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Ashok
authors.initials: A
authors.lastname: Bera
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Arif D
authors.initials: AD
authors.lastname: Sheikh
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Md Azimul
authors.initials: MA
authors.lastname: Haque
authors.affiliation: Solar and Photovoltaics Engineering Research Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Riya
authors.initials: R
authors.lastname: Bose
authors.affiliation: Solar and Photovoltaics Engineering Research Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Erkki
authors.initials: E
authors.lastname: Alarousu
authors.affiliation: Solar and Photovoltaics Engineering Research Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Omar F
authors.initials: OF
authors.lastname: Mohammed
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Tom
authors.initials: T
authors.lastname: Wu
keywords: Zn2SnO4; electron transport layer; perovskite solar cells; transient absorption spectroscopy