Year: 2026
Type: preprint
Abstract: Spherulites-iconic, radially textured growth forms in polymers-are shown here to form reproducibly in lead-halide perovskite hydrates on glass.Using Hygro-Triggered Giant Spherulites Formation (HT-GSF), a routine solution-processed perovskite precursor is converted into single-nucleus spherulitic films that expand radially to centimetre scale (up to >1 cm).Real-time optical microscopy captures the moving growth front and records the moment it engulfs and incorporates surrounding particles, providing direct video evidence of particle assimilation during spherulite growth in this materials system.Subsequent annealing converts the white hydrate-derived network into black perovskite while retaining a pronounced out-of-plane (110) texture, yielding centimetre-scale, strongly oriented spherulites with markedly fewer macroscopically visible high-angle grain boundaries than conventional spin-coated films.Under ambient-air ageing, HT-GSF films show only weak hydrate-related signatures after one week, whereas control films exhibit rapid hydrate formation and visible degradation within hours.These findings demonstrate that controlled humidity exposure can be used as a deliberate processing step to engineer large-scale, highly textured perovskite films with improved ambient stability.The stochastic nucleation pattern and macroscopic scale of the resulting films suggest potential utility in physically unclonable function (PUF) applications.
Source: ChemRxiv
Author: Hiroto T. Murakami
Institutions: Okayama University, Nara Institute of Science and Technology
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223067998