Znwo4:Eu(3+)Phosphor With Intense Blue Led Excitation: Photoluminescence And Electron Density Distribution Analysis

A high intensity 464 nm excitable ZnWO4:Eu(3+)red-emitting phosphor for warm white lighting applications was prepared using a solid-state reaction method by varying the dopant Eu(3+)concentration. Crystalline purity and phase identification was confirmed and revealed using powder X-ray diffraction and Rietveld refinement analysis. The surface morphology of Zn1-xEuxWO4(x = 0, 0.01, 0.02, 0.03, 0.04 and 0.05) was examined using scanning electron microscopy (SEM) techniques. From SEM analysis, the ZnWO4:Eu(3+)phosphor prepared at 1-3% molar Eu(3+)concentrations exhibited a small pebble-like morphology with a smooth surface. On increasing the molar concentration of Eu(3+)to >3%, the pebble stone morphology disappeared and a large, smooth irregular polygon-shaped granular-like morphology was obtained. Of the higher mol% Eu3+, the 4% Eu3+-doped ZnWO(4)showed the best photoluminescence properties with high intensity and sharp excitation at 395 and 464 nm, followed by red emission centred at 615 nm with excellent CIE coordinates (x = 0.58 and y = 0.41) in the core red region. Elemental composition and chemical state analysis were carried out for the 4% Eu3+-doped ZnWO(4)phosphor using X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy studies. Based on all the above analyses, the Eu3+-doped ZnWO(4)phosphor was found to be a very efficient red-emitting phosphor under near-UV light as well as under visible light excitation and could be used for white LED and field emissive displays applications.