Advances in Beamline in situ Spin-Coating for Perovskite Thin Films and Beyond

Abstract

This research letter presents a beamline-integrated in situ spin coater that enables real-time observation of thin-film formation and crystallization during spin coating and annealing. The system integrates temperature-stable heating, low-vibration motors, and a helium-purged inert chamber with synchronized anti-solvent injection and detector acquisition at millisecond resolution. Controlled through a LabView interface, synchronized triggers coordinate spin speed, anti-solvent delivery, and data collection within the beamline environment. Applied to Cs0.1FA0.9PbI3 films passivated with PEACl, time-resolved grazing-incidence X-ray scattering (GIWAXS) reveals transient Pb–Cl–I intermediates that vanish as 3D perovskite phases form. The evolution of quasi-2D domains, lattice contraction, and crystallite orientation directly correlates with nucleation and passivation dynamics. This approach provides a general framework for linking processing conditions to structural evolution in perovskite and other functional thin films.