Facile phase tuning of CsCdCl3:Mn2+ phosphor for nearly-unity quantum yield and extended afterglow

• • 10% Mn2+ doping in cubic CsCdCl3 achieves near-unity PL QY and 10 h afterglow, enabling high-efficiency persistent luminescence for information storage and anti-counterfeiting. • • Phase transition from cubic to hexagonal occurs at 100 °C, with Mn2+ concentration as a tunable parameter, allowing precise control over lattice structure for tailored optical properties. • • X-ray imaging resolution reaches approximately 6 lp/mm, and luminescence intensity remains stable after 10 min of X-ray irradiation, indicating suitability for radiation detection and imaging. • • Information retrieval via heating at 125 °C demonstrates practical optical data storage with thermal readout, while hand-printed patterns on PET show potential for flexible anti-counterfeiting labels.