title: Mixed-Organic-Cation (FA)x(MA)1-xPbI3Planar Perovskite Solar Cells with 16.48% Efficiency via a Low-Pressure Vapor-Assisted Solution Process.
abstract: Compared to that of methylammonium lead iodide perovskite (MAPbI3), formamidinium lead iodide perovskite (FAPbI3) has a smaller energy band gap and greater potential efficiency. To prevent the transformation of α-FAPbI3to δ-FAPbI3, preparation of (FA)x(MA)1-xPbI3was regarded as an effective route. Usually, the planar (FA)x(MA)1-xPbI3perovskite solar cells are fabricated by a solution process. Herein, we report a low-pressure vapor-assisted solution process (LP-VASP) for the growth of (FA)x(MA)1-xPbI3perovskite solar cells that features improved electron transportation, uniform morphology, high power conversion efficiency (PCE), and better crystal stability. In LP-VASP, the (FA)x(MA)1-xPbI3films were formed by the reaction between the PbI2film with FAI and MAI vapor in a very simple vacuum oven. LP-VASP is an inexpensive way to batch-process solar cells, avoiding the repeated deposition solution process for PbI2films, and the device had a low cost. We demonstrate that, with an increase in the MAI content, the (101) peak position of FAPbI3shifts toward the (110) peak position of MAPbI3, the (FA)x(MA)1-xPbI3perovskites are stable, and no decomposition or phase transition is observed after 14 days. The photovoltaic performance was effectively improved by the introduction of MA+with the highest efficiency being 16.48% under conditions of 40 wt % MAI. The carrier lifetime of (FA)x(MA)1-xPbI3perovskite films is approximately three times longer than that of pure FAPbI3. Using this process, solar cells with a large area of 1.00 cm2were fabricated with the PCE of 8.0%.
authors.affiliation: State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University , Beijing 102206, China.|Beijing Key Laboratory of Energy Safety and Clean Utilization, North China Electric Power University , Beijing 102206, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University , Beijing 102206, China.|Beijing Key Laboratory of Novel Film Solar Cell, North China Electric Power University , Beijing 102206, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University , Beijing 102206, China.|Beijing Key Laboratory of Novel Film Solar Cell, North China Electric Power University , Beijing 102206, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University , Beijing 102206, China.|Beijing Key Laboratory of Energy Safety and Clean Utilization, North China Electric Power University , Beijing 102206, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University , Beijing 102206, China.|Beijing Key Laboratory of Novel Film Solar Cell, North China Electric Power University , Beijing 102206, China.
authors.forename: Songyuan
authors.initials: S
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University , Beijing 102206, China.|Beijing Key Laboratory of Energy Safety and Clean Utilization, North China Electric Power University , Beijing 102206, China.
authors.forename: Jianxi
authors.identifier: http://orcid.org/0000-0002-5472-9337
authors.initials: J
authors.lastname: Yao
keywords: mixed-organic-cation lead halide perovskite; perovskite solar cells; planar heterojunction; power conversion efficiency; vapor-assisted deposition