Energy transfer and red fluorescence properties of (Ce3+/Eu3+):Fluorophosphate glasses for lighting applications

Intense bluish-red color de-excitation by combining Ce3+ and Eu3+ ions has been observed in fluorophosphate (P2O5+K2O+Al2O3+BaF2+NaF2 (PKABfNf)) glasses which were fabricated by adopting conventional melting and rapid quench technique. Photoluminescence spectra, lifetimes, and energy transfer (ET) process in the Ce3+/Eu3+:PKABfNf glasses were studied. The fluorescence spectra of co-doped glasses exhibit broad band emission at blue corresponding to Ce3+ ions which can enhance the intensity of the red emission of Eu3+ via an efficient ET mechanism. The ET from Ce3+to Eu3+ can be explained based on the Blasse's equation and Dexter's theory of resonant ET. Furthermore, critical ET separation of distance (Rc), luminous efficiency due to energy transfer (ηET), CIE chromaticity co-ordinates (x,y), correlated color temperature (CCT) and color purity (CP) were calculated. The results reveal that the optimized Ce3+/Eu3+:PKABfNf glass can be a potential candidate for w-LEDs in lighting applications. © 2020 Elsevier B.V.