Pure Red Emission with Spectra-Stable in Full Iodine-based Quasi-2D Perovskite Films by Controlling Phase Distribution

Quasi-2D perovskites have emerged as a promising candidate material for displays owing to their high photoluminescence quantum yields and low-cost solution synthesis. However, achieving pure red quasi-2D perovskite films with luminescence centered at 630 nm and a narrow emission band presents a critical challenge for high-definition display. Herein, via incorporating 18-crown-6 as additives that simultaneously passivates the defects and regulates phase distribution, full iodine-based quasi-2D perovskite films with single red emission peak and spectra-stable are designed. Additionally, through introducing appropriate chlorobenzene and enhancing annealing temperature resulting in a narrower phase distribution, the full width at half maximum (FWHM) of emission peak is significantly reduced. After the optimized process, we fabricate quasi-2D perovskite films with pure red emission, which exhibit a PL peak at 627.9 nm and a narrow FWHM of 45.1 nm. Based on these pure red perovskite films, diverse complex patterns such as fluorescent anti-counterfeiting labels are implemented for data storage and information encryption. This study provides an effective approach to developing quasi-2D perovskite with high color purity for high-definition purposes.text goes here.