Optical Properties of NaCl:Sn2+ Phosphor Synthesized from Aqueous NaCl/SnCl2/HCl Solution

A NaCl:Sn2+ phosphor was synthesized from an aqueous NaCl/SnCl2/HCl solution. The optical properties of the as-synthesized phosphor material were investigated by diffuse reflectance spectroscopy, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and luminescence decay time measurement. The effects of temperature and excitation wavelength on the emission spectra were thoroughly studied in the present study. The temperature dependence of the PL spectra was examined between T = 20 and 300 K in 10 K increments, while the PLE spectra were obtained by excitation with λex ∼ 250-330 nm in the same temperature range. The PL spectra revealed four independent emission bands with peaks at ∼440 nm (B1), ∼490 nm (B2), ∼540 nm (G), and ∼635 nm (R). The B1 and G emission bands were assigned to the AT and AX emission bands typically observed in ns2-doped alkali halide phosphors, whereas the B2 and R emission bands were attributed to the Sn2 + − V−Na (cation vacancy) dipole aggregates.