title: Stabilized Wide Bandgap Perovskite Solar Cells by Tin Substitution.
abstract: Wide bandgap MAPb(I1-yBry)3perovskites show promising potential for application in tandem solar cells. However, unstable photovoltaic performance caused by phase segregation has been observed under illumination when y is above 0.2. Herein, we successfully demonstrate stabilization of the I/Br phase by partially replacing Pb2+with Sn2+and verify this stabilization with X-ray diffractometry and transient absorption spectroscopy. The resulting MAPb0.75Sn0.25(I1-yBry)3perovskite solar cells show stable photovoltaic performance under continuous illumination. Among these cells, the one based on MAPb0.75Sn0.25(I0.4Br0.6)3perovskite shows the highest efficiency of 12.59% with a bandgap of 1.73 eV, which make it a promising wide bandgap candidate for application in tandem solar cells. The engineering of internal bonding environment by partial Sn substitution is believed to be the main reason for making MAPb0.75Sn0.25(I1-yBry)3perovskite less vulnerable to phase segregation during the photostriction under illumination. Therefore, this study establishes composition engineering of the metal site as a promising strategy to impart phase stability in hybrid perovskites under illumination.
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Adharsh
authors.initials: A
authors.lastname: Rajagopal
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Sae Byeok
authors.initials: SB
authors.lastname: Jo
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Chu-Chen
authors.initials: CC
authors.lastname: Chueh
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Spencer
authors.initials: S
authors.lastname: Williams
authors.affiliation: Department of Chemical Engineering, Molecular Engineering and Sciences Institute, University of Washington , Seattle, Washington 98195-1750, United States.
authors.forename: Chun-Chih
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Chemical Engineering, Molecular Engineering and Sciences Institute, University of Washington , Seattle, Washington 98195-1750, United States.
authors.forename: John K
authors.initials: JK
authors.lastname: Katahara
authors.affiliation: Department of Chemical Engineering, Molecular Engineering and Sciences Institute, University of Washington , Seattle, Washington 98195-1750, United States.
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Hillhouse
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Alex K-Y
authors.initials: AK
authors.lastname: Jen
keywords: Large bandgap; Sn substitution; phase segregation; photo stability