Study on the luminescence properties and energy transfer of Na4CaSi3O9:Ce3+, Sm3+ phosphor

In this work, we synthesize successfully Na4CaSi3O9:R (R = Ce3+, Sm3+, and Ce3+/Sm3+) phosphors in the reducing atmosphere (95% N-2 + 5% H-2) by using the high-temperature solid-state method. The crystal structure and luminescence properties of samples are investigated. The excitation spectrum of Na4CaSi3O9:Ce3+ phosphor is observed in the range of 220-400 nm due to the 4f -> 5d transitions of Ce3+ ion. The emission spectrum contered at similar to 425 nm of Na4CaSi3O9:Ce3+ phosphor is in the range of 360-650 nm owing to the 5d -> F-2(5)/(2) and F-2(7/2) transitions of Ce3+ ion. Na4CaSi3O9:Sm3+ phosphor can show the excitation spectrum in the range of 200-550 nm owing to the O2- - Sm3+ charge transfer band and the f - f transitions of Sm3+ ion, and its emission spectrum covers the region from 575 nm to 750 nm with four emission bands because of the (4)G(5/2) -> H-6(5/2), H-6(7/2), H-6(9/2), and H-6(11/2) transitions of Sm3+ ion. The tunable emission, luminescence improvement, temperature-dependent emission, and lifetime in Na4Ca0.96-xSi3O9:4 mol%Ce3+, xSm(3+) phosphors are investigated. The luminous mechanism of Na4CaSi3O9:Ce3+, Sm3+ phosphors is explained by using the energy level diagrams of Ce3+ and Sm3+ ions. The experimental results are beneficial to research new Ce3+ and Sm3+ co-doped phosphors.

Automated summary

In this study, Na4CaSi3O9 phosphors doped with Ce3+, Sm3+, and Ce3+/Sm3+ were successfully synthesized under a reducing atmosphere using the high-temperature solid-state method. The crystal structure and luminescence properties of the samples were investigated, and the effects of different dopant ions on the emission spectra were studied. The results provide valuable insights for researching new Ce3+ and Sm3+ co-doped phosphors, and the emission mechanisms were explained using energy level diagrams of Ce3+ and Sm3+ ions.