The influence of Ag⁹⁺ ion irradiation on the structural, optical and luminescence properties of Sm³⁺ doped NaSrBO₃: Stability of color emission

This paper reports on the effect of 120 MeV Ag⁹⁺ ion irradiation on the structure, optical and luminescence properties of NaSr_1-xBO₃: xSm³⁺ (x = 0.5-2.5 mol.%) phosphor, synthesized by the solid state reaction and combustion method. The samples were irradiated with Ag⁹⁺ swift heavy ions (SHIs) using fluences of 1 × 10¹² ions cm^-2, 5 × 10¹² ions cm^-2 and 1 × 10¹³ ions cm^-2. The as-prepared as well as irradiated samples were characterized by X-ray diffraction (XRD), diffuse reflectance (DR) and photoluminescence (PL) techniques. After irradiation, the structure of the phosphor did not change except that the loss of crystallinity which may be due to the fragmentation caused by the SHI. DR spectra reflect a blue shift in the absorption band with increasing fluences, for phosphors prepared using both solid state reaction and combustion method, resulting in an increase in the band gap from 5.64 to 6.06 eV. The PL intensity of the phosphors was enhanced with an increase in ion fluences, with the samples prepared using a combustion method exhibiting prominent intensity. The CIE coordinates were calculated and they correspond to the shade of orange-red emission of the Sm³⁺ ions.