Tunable blue–white–red photoluminescence and long lasting phosphorescence properties of a novel zirconate phosphor: La2Zr2O7:Sm3+,Ti4+

Abstract

Abstract A novel long lasting phosphorescence phosphor La 2 Zr 2 O 7 :Sm 3+ ,Ti 4+ is firstly synthesized by solid state method at 1673 K in air. The emission spectrum of La 2 Zr 2 O 7 :Sm 3+ ,Ti 4+ consists of a broad band at 460 nm due to charge transfer of O 2 − –Ti 4+ and the emission lines of Sm 3+ in 550–700 nm. By changing the co-doping content of Sm 3+ , the color of photoluminescence and long lasting phosphorescence are tunable and the blue, red even white color can be observed. The spectral overlap reveals the presence of efficient energy transfer between Ti 4+ and Sm 3+ . The long lasting phosphorescence of the optimal sample can be recorded for about 540s(0.32mcd/m 2 ) and the decay curve can not be exponentially fitted for the presence of two decay origins. It reveals that the Sm 3+ and Ti 4+ ions act as not only emission centers but also aliovalent auxiliaries to create proper shallow traps clusters. Additionally, the deep traps (342 K and 411 K) are proved to be stable enough that the La 2 Zr 2 O 7 :Sm 3+ ,Ti 4+ material shows potential applications as not only a long lasting phosphorescence phosphor but also an optical storage material.