Red-emitting double perovskite phosphors Sr1−xCaxLaMgSbO6:Eu3+: Luminescence improvement based on composition modulation

Abstract Crystal structures of Sr 1- x Ca x LaMgSbO 6 :Eu 3+ phosphors were studied in detail. Both the SrLaMgSbO 6 and the CaLaMgSbO 6 have a monoclinic ( P 2 1 / n ) structure. With increasing the Ca 2+ concentration, the peaks gradually divided and the phase changed from SrLaMgSbO 6 to CaLaMgSbO 6 . The symmetry of La 3+ in SrLaMgSbO 6 is lower than that in CaLaMgSbO 6 . Eu 3+ ions, as the structural probes, were selected to study the structure. Lifetimes and intensity ratio were used to study the symmetry in the structure. Thermal quenching of the phosphors was discussed from 323 K to 473 K. The emission intensities of 5 D 1 → 7 F J and 5 D 0 → 7 F J damped in different ratios while increasing temperature. The configurational coordinate diagram was used to explain this interesting phenomenon.