title: Morphology Evolution of High Efficiency Perovskite Solar Cells via Vapor Induced Intermediate Phases.
abstract: Morphology is critical component to achieve high device performance hybrid perovskite solar cells. Here, we develop a vapor induced intermediate phase (VIP) strategy to manipulate the morphology of perovskite films. By exposing the perovskite precursor films to different saturated solvent vapor atmospheres, e.g., dimethylformamide and dimethylsufoxide, dramatic film morphological evolution occurs, associated with the formation of different intermediate phases. We observe that the crystallization kinetics is significantly altered due to the formation of these intermediate phases, yielding highly crystalline perovskite films with less defect states and high carrier lifetimes. The perovskite solar cells with the reconstructed films exhibits the highest power conversion efficiency (PCE) up to 19.2% under 1 sun AM 1.5G irradiance, which is among the highest planar heterojunction perovskite solar cells. Also, the perovskite solar cells with VIP processing shows less hysteresis behavior and a stabilized power output over 18%. Our work opens up a new direction for morphology control through intermediate phase formation, and paves the way toward further enhancing the device performances of perovskite solar cells.
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.|California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Lijian
authors.initials: L
authors.lastname: Zuo
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.
authors.forename: Shiqi
authors.initials: S
authors.lastname: Dong
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.|California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Nicholas
authors.initials: N
authors.lastname: De Marco
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.|California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Yao-Tsung
authors.initials: YT
authors.lastname: Hsieh
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.|California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Bae
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Sun
authors.affiliation: Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States.|California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang