Topological polar textures on CsPbBr3 nanoplatelets

Abstract

Polar topological textures like the bubble domains, flux closures, labyrinths, etc., unlock functional responses in ferroic systems but are difficult to stabilize and control in chemically simple, solution-grown materials. Here, we show that ultra-thin, large-area CsPbBr3 nanoplatelets host room-temperature ferroelectric bubble domains whose characteristic size is tunable by thickness. Using contact resonance piezoresponse force microscopy across 125 nm-2 μ m, we observe a systematic decrease in domain size with decreasing thickness, consistent with a depolarization field-controlled stability window. Repeated scanning transforms bubbles into labyrinthine patterns, indicating metastability under weak mechanical/electrical perturbations. Upon heating, bubbles evolve into labyrinths and vanish at T c ≈ 90 ° C, with nucleation recovered on cooling. These results establish a controllable platform for polar topology in solvothermally grown stoichiometric perovskite, showing how thickness and temperature set boundary conditions that govern texture selection. The thickness-tunable polar textures identified here offer a route to engineer domain wall-mediated functionalities in halide perovskites.