Optimizing annealing temperature for dysprosium-doped zinc silicate nanophosphors: unveiling structural advancements and luminescent characteristics for high-performance LED technology

Dysprosium-doped Zinc silicate nanophosphors, synthesized via co-precipitation, were studied for their properties under varying annealing temperatures. Increasing annealing temperature improved crystallinity in 0.5 mol% Dy3+doped Zn2SiO4, affirming enhanced phase stability and structural integrity. UV–Vis spectroscopy highlighted an indirect bandgap of 5.76 eV and 5.71 eV for samples annealed at 600 °C and 1100 °C, respectively. Photoluminescence assessments, conducted at excitation and emission wavelengths of 350 nm and 574 nm, respectively, revealed broad excitation peaks due to multiple Stark level transitions between Dy3+ ion levels. The dominant emission peak was identified at 392 nm, corresponding to the 4H15/2 → 6K17/2 transitions in Dy3+ ions. Additional emission transitions for Dy3+ ions were observed at 470 nm and between 484 and 494 nm. The CIE coordinates indicate that the Zn2SiO4 doped with 0.5 mol% Dy3+ predominantly emits in the white luminescence region. The high photoluminescence intensity, stability, and tunable emission properties of Zn₂SiO₄: Dy3⁺ making it a strong candidate for applications in white LEDs, display backlights, and optical sensors.