Effect of swift heavy ion irradiation on structural, optical and luminescence properties of SrAl2O4:Eu2+, Dy3+ nanophosphor

• The effect of energy deposition in long persistent SrAl2O4:Eu2+, Dy3+ nanophosphor have been discussed.
• The decrease in PL intensity after irradiation confirms the introduction of additional deep defect levels.
• The TL glow curve of the irradiated phosphors showed a broad band with intermediate kinetics.

The effect of energy deposition by swift heavy ion (SHI) irradiation on the structural, optical and luminescence properties of the SrAl2O4:Eu2+, Dy3+ nanophosphor synthesized by a combustion method has been presented. The samples were irradiated with 120 MeV Ag9+ SHIs at fluences in the range of 1×1012 ions cm−2 to 1×1013 ions cm−2. The X-ray diffraction results revealed that the obtained powder corresponds to the monoclinic-phase with space group P21 and the results also indicate that the SHI irradiation did not cause any change in the crystal structure of the phosphor. However, a decrease in the crystallinity was observed. Under 330 nm excitation, the PL emission spectra show a broad band centered at 516 nm which corresponds to the 4f65d→4f7(8S7/2) transition of the Eu2+ ion. The PL intensity of the phosphors was found to decrease with an increase in the ion fluences, which may be due to the enhancement in the non-radiative recombination via additional deep level traps introduced by the SHI irradiation. SHI irradiation enhanced the phosphorescence life time of the phosphors. After SHI irradiation, a blue shift in the diffuse reflectance spectra was observed. The thermoluminescent (TL) glow curve of the SHI irradiated phosphors showed a broadband with a shift in the peak position from 375 K to 391 K with an increase in the ion fluence. Also, the TL intensity has increased with an increase in the ion fluences.