Solution-Phase Halide Exchange and Targeted Annealing Kinetics in Lead Chloride Derived Hybrid Perovskites
journal contributionposted on 2020-09-03, 16:03 authored by Vivek Thampy, Kevin H. Stone
Hybrid perovskites are a promising class of materials for a range of optoelectronic applications. Many material properties are dictated by the details of the synthetic process, yet a mechanistic understanding is lacking for the majority of these materials. We have studied the formation of methylammonium lead iodide films derived from a lead chloride precursor to understand both the casting solution chemistry and its influence on the final, largely chlorine-free, film. Using solution-phase extended X-ray absorption spectroscopy, we observe a halide exchange with the primary solution plumbate species identified as PbI2.5Cl0.33. The mixed halide plumbate solution species leads to formation of the crystalline intermediate phase of (CH3NH3)2PbI3Cl. Using in situ synchrotron X-ray diffraction, we show that compositional control of the casting solution can control the annealing kinetics of film formation. Our study demonstrates the importance of solution-phase chemistry and its impact on lead halide perovskite synthesis.
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film formationX-ray absorption spectroscopysolution plumbate speciesoptoelectronic applicationshalide exchangeLead Chloride Derived Hybrid Perovs...solution chemistry2 PbI 3 Clsynchrotron X-ray diffractionhalide perovskite synthesischloride precursorSolution-Phase Halide Exchangehalide plumbate solution speciesPbI 2.5 Cl 0.33iodide filmsMany material propertiesTargeted Annealing KineticsCH 3 NH 3solution-phase chemistryannealing kinetics