Synthesis of pure Zn₂SiO₄:Mn green phosphors by simple PVA–metal complex route

Green light emitting Zn_2−x Mn _x SiO₄ (willemite) particles were synthesized by a simple and cost-effective poly(vinyl alcohol) (PVA)-complex route. Microstructural studies on the calcined products show that particles are pure, single phase, nano-crystalline, and agglomerated morphology. A pure-phase willemite structure was obtained with calcination between 850 and 1,175 °C for 2 h in air. Particle size analysis indicates that the average particle size is ∼1 μm. The photoluminescence properties of these 4 and 12 mol% Mn-doped Zn₂SiO₄ powders were measured by fluorescence spectroscopy. Particles with 4 mol% Mn doping prepared at 1,150 °C, with an emission decay time, I ₀/e, of 13.4 ms showed the highest relative peak emission intensities. The emission intensity at this doping level was measured to be ∼110% of a representative commercial product’s, doped with 11.2 mol% Mn, and exhibiting a decay time of 7.1 ms. The effect of calcination temperature on the photoluminescence and crystallinity properties of synthesized green powders was also investigated.