Synthesis and luminescence studies of NaSr4(BO3)3:Dy3+ phosphors

The polycrystalline sample of dysprosium doped NaSr4 (BO3)3 is prepared by employing modified solution combustion synthesis method. The as-synthesized phosphors were characterized by X-ray powder diffraction (XRD), photoluminescence excitation (PLE) and photoluminescence (PL) spectra. By Exposing with gamma-rays, its thermoluminescence properties were studied. Kinetic parameters were calculated using peak shape method. The effect of dose variation of gamma rays on NaSr4 (BO3)3 were also studied. The PLE spectra show the excitation peaks from 300 nm to 400 nm is due to the 4f–4f transitions of Dy3+. This mercury-free excitation is useful for solid state lighting and light-emitting diodes. The emission of Dy3+ ions upon 350 nm excitation, is observed at 482 nm (blue) due to the 4F9/2 → 6H15/2 transitions and 574 nm (yellow) due to 4F9/2 → 6H13/2 transitions. The CIE chromaticity coordinates (x = 0.35 and y = 0.40) for NaSr4 (BO3)3:Dy3+ phosphors are simulated and located in the bluish-white region