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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 22: Perovskite and Photovoltaics II (joint session HL/KFM)
KFM 22.12: Talk
Thursday, March 21, 2024, 12:30–12:45, EW 203
Growth and Investigation of Sequentially Evaporated Mixed Halide (Cs,FA)Pb(I,Br)3 Perovskites — •Tobias Schulz1, Karl Heinze1, Paul Pistor2, and Roland Scheer1 — 1Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Saale), Germany — 2Universidad de Pablo de Olavide, Carretera de Utrera 1, 41013 Sevilla, Spain
Perovskite films were grown via thermal evaporation and characterized via in situ XRD which give structural information in real-time. Besides the growth of FAPbI3 and (Cs,FA)PbI3 also bromine incorporation into the perovskite to prepare (Cs,FA)Pb(I,Br)3 was investigated [1]. The substitution of iodine with bromine increases the band gap, which is interesting for tandem applications, and improves the thermal stability. In contrast to co-evaporation, the less studied sequential evaporation route was employed which allows a more precise process control. Sequential perovskite formation in vacuum in general proceeds via diffusion of the reactants CsI, FAI, PbI2, and PbBr2 which are assembled in different layer stacks. With the in situ XRD setup, the diffusion of these materials during the necessary annealing step was observed. In combination with SEM images, the reactant's diffusion speed was quantified. Additionally, the perovskites show no unfavourable delta-phase during our experiments, allowing the assumption, that sequential evaporation can fully suppress this non-photoactive phase. [1]: K. Heinze, T. Schulz et al., "Structural Evolution of Sequentially Evaporated (Cs,FA)Pb(I,Br)3 Perovskite Thin Films via In Situ XRD", Physica Status Solidi A, accepted for publication
Keywords: Perovskite; Thermal Evaporation; Sequential Evaporation; In Situ XRD