title: Manipulating Crystallization of Organolead Mixed-Halide Thin Films in Antisolvent Baths for Wide-Bandgap Perovskite Solar Cells.
abstract: Wide-bandgap perovskite solar cells (PSCs) based on organolead (I, Br)-mixed halide perovskites (e.g., MAPbI2Br and MAPbIBr2 perovskite with bandgaps of 1.77 and 2.05 eV, respectively) are considered as promising low-cost alternatives for application in tandem or multijunction photovoltaics (PVs). Here, we demonstrate that manipulating the crystallization behavior of (I, Br)-mixed halide perovskites in antisolvent bath is critical for the formation of smooth, dense thin films of these perovskites. Since the growth of perovskite grains from a precursor solution tends to be more rapid with increasing Br content, further enhancement in the nucleation rate becomes necessary for the effective decoupling of the nucleation and the crystal-growth stages in Br-rich perovskites. This is enabled by introducing simple stirring during antisolvent-bathing, which induces enhanced advection transport of the extracted precursor-solvent into the bath environment. Consequently, wide-bandgap planar PSCs fabricated using these high quality mixed-halide perovskite thin films, Br-rich MAPbIBr2, in particular, show enhanced PV performance.
authors.affiliation: School of Engineering, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Chemistry and Nanoscience Center, National Renewable Energy Laboratory , Golden, Colorado 80401, United States.
authors.forename: Mengjin
authors.initials: M
authors.lastname: Yang
authors.affiliation: School of Engineering, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Onkar S
authors.initials: OS
authors.lastname: Game
authors.affiliation: School of Engineering, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Wu
authors.affiliation: School of Engineering, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Joonsuh
authors.initials: J
authors.lastname: Kwun
authors.affiliation: School of Engineering, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Strauss
authors.affiliation: Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo , Toledo, Ohio 43606, United States.
authors.forename: Yanfa
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Mechanical and Materials Engineering, Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Huang
authors.affiliation: Chemistry and Nanoscience Center, National Renewable Energy Laboratory , Golden, Colorado 80401, United States.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhu
authors.affiliation: School of Engineering, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Nitin P
authors.initials: NP
authors.lastname: Padture
keywords: antisolvent−solvent extraction; grain growth; nucleation; solar cells; wide-bandgap perovskite