Wet-chemical synthesis of ZnGa₂S₄: Eu²⁺ thiogallate phosphor

The wet-chemical co-precipitation method is used to prepare the ternary sulphide ZnGa₂S₄ phosphor doped with Eu²⁺. The synthesized product was characterized using XRD, scanning electron microscopy, Energy dispersive spectra, elemental mapping dynamic light scattering for particle size distribution. The phosphor shows emission band centred at 540 nm. The excitation is over a broad range covering near ultraviolet through blue region of the spectrum. Maximum photoluminescence intensity was obtained for 5 mol% Eu. Intensity decreased due to multipolar interactions at higher concentrations. The critical distance was obtained as 20.14 Å. The phosphor shows nearly perfect colour coordinates for green emission with colour purity of 97%. The method can be easily extended for preparing other sulphide phosphors.