Blue–violet emitting K₂CuCl₃ compound: facile synthesis, photoluminescence and radioluminescence properties

Abstract: Copper-based lead-free perovskite derivatives have recently drawn great attention for their excellent optoelectronic properties and potential applications in light-emitting diodes (LEDs) and photodetectors. Herein, facile synthesis methods of cooling crystallization and wet ball milling (WBM) are adopted to synthesize K₂CuCl₃, resulting in single crystals (SCs) and powder samples, respectively. The as-fabricated K₂CuCl₃ samples exhibit blue–violet emission, with the highest photoluminescence quantum yield (PL QY) of 70% (under 280 nm excitation), and the photoluminescence (PL) is attributed to the self-trap excitons (STEs) emission. We also test the scintillation properties of K₂CuCl₃ for X-ray detection and imaging applications. A down-conversion LED is finally made by using K₂CuCl₃ as phosphor. Graphical abstract: [Figure not available: see fulltext.]As-synthesized K2CuCl3 can be used for either photoluminescence under UVlight or X-ray imaging under X-ray radiation.