Year: 2026
Type: preprint
Abstract: Quasi-2D Ruddlesden-Popper halide perovskites are promising materials for light-emitting applications. They comprise corner-sharing metal-halide octahedra separated by bulky, insulating organic spacers and exhibit tunable bandgaps by varying the number of octahedral layers, n . Isolating a single n -phase within a film remains challenging, with spin-coated films generally containing a broad distribution of n phases. Their emission is dominated by the largest n -number present due to energy funneling towards narrow bandgap phases. Here, we electrospin phenylethylammonium (PEA + )/methylammonium (MA + ) lead bromide quasi-2D perovskites into 140 - 400 nm nanofibers to restrict molecular diffusion. We observe progressive redshifts in absorption and photoluminescence from blue (410 nm) to cyan (470 nm) to green (530 nm) with decreasing PEA + :MA + molar ratio. In contrast, spin-coated films with the same PEA + :MA + ratios exhibit green emission (524 - 532 nm) across all MA + containing compositions. Transient absorption spectroscopy reveals energy transfer within 80 ps from low n phases to MAPbBr 3 domains in spin-coated films, which are absent in electrospun fibers. Electrospun fibers are also highly emissive compared to spin-coated films, with average photoluminescence quantum yields up to 77±1%. These results suggest that electrospinning limits organic cation diffusion to selectively stabilize intermediate n phases, providing a scalable route to achieve tunable solid-state emission.
Source: ChemRxiv
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223188278