Photoluminescence and thermoluminescence analysis of Zn2SiO4:Dy3+ nanophosphor

Highlights: • Sol-gel, PL and TL properties of dysprosium (Dy³⁺) doped Zn₂SiO₄ are presented. • XRD shows crystalline peaks corresponding to α-Zn₂SiO₄ phase. • Intense PL emission peak was observed with the doping concentration of 2 mol% Dy³⁺. • CIE coordinates showed Zn₂SiO₄: 2 mol % Dy³⁺is useful for white light application. • TL glow curve showed sample with 2 mol% of Dy³⁺ ion has adequate glow for dosimetry. This work illustrates the sol-gel synthesis of dysprosium (Dy³⁺)-doped zinc silicate (Zn₂SiO₄) nanophosphor. The studies to evaluate its properties for possible application in solid state lighting and dosimetry were done. Synthesized nanophosphors were characterized using an X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to investigate structure and morphology. Photoluminescence (PL) properties were also investigated under ultraviolet excitation. XRD results revealed α-Zn₂SiO₄ crystallite phase whereas the morphology of spherical nanoparticles was observed with the sonication time of 3 h. The excitation spectrum was obtained with the main peak located at ~350 nm attributed to ⁶H_15/2 ground state and ⁶P_7/2 excited state of Dy³⁺ ions. Relatively high PL emission was observed with a sample with 2 mol% of Dy³⁺ ions and the spectra exhibited a broad and narrow peaks positioned at ~418 nm, 435 nm and 478 nm (blue), ~574 nm (yellow) and (red) emission at ~660 nm corresponding to optical transitions of Dy³⁺ ions. Thermoluminescence (TL) glow curves of the samples irradiated by a beta source revealed three peaks at ~90, 180 and 375 °C. The intensity of the signal was improving with an increase of the irradiation from 1.58 to 100.86 Gy. The TL repeatability and fading signal trend showed experimental evidence which suggests that Zn₂SiO₄:2 mol% Dy³⁺ is a promising phosphor for dosimetry application.