Regensburg 2022 – wissenschaftliches Programm
KFM 27.5: Vortrag
Donnerstag, 8. September 2022, 16:00–16:15, H31
Extensive study on sequential physical vapor deposition of mixed-cation perovskite (Cs,FA)PbI_3 — •Karl Heinze1, Tobias Schulz1, Roland Scheer1, and Paul Pistor2 — 1Institute of Physics, Martin-Luther-University Halle-Wittenberg, von-Danckelmann-Platz 3, 06120 Halle (Saale), Germany — 2Universidad de Pablo Olivade, Carretera de Utrera 1, 41013, Sevilla, Spain
Sequential deposition via physical vapor deposition (PVD) is underexplored, even though it offers precise adjustment of components and composition and a variety of routes to investigate the optimization of perovskite growth. We combine in situ XRD and in situ laser light scattering to monitor phase evolution of (Cs,FA)PbI3 during PVD. We study the influence of deposition sequence of the components PbI2, FAI and CsI on CsFAPbI3 growth. Noticeably, the sequence strongly influences the orientation of deposited components. Similarly, diffusion before and during annealing as well as resulting alpha phase share depend on the evaporation sequence. When depositing PbI2 first, conversion to the perovskite phase was not achieved, unless an over stoichiometric share of FAI was deposited. Depositing FAI first and PbI2 later resulted in a high probability of layer conversion to the perovskite phase without secondary phases being detected. A striking feature during our investigation was the absence of the delta phase during deposition and annealing, seemingly caused solely by the preparation method. We deliver important insight into this poorly investigated preparation path and provide a foundation for further research based on our detailed study of sequence-dependent crystalline growth.