Synthesis and characterization of Zn2GeO4:Mn2+ phosphor for field emission displays

Zn2-2xMn2xGeO4 (x = 0, 0.001, 0.01) phosphors were prepared by conventional solid state reaction technique. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), diffuse reflection spectra, photoluminescence (PL), and cathodoluminescence (CL) spectroscopy were utilized to characterize the synthesized phosphors. The Mn2+-activated Zn2GeO4 phosphors exhibit narrow emission band at 532 nm under the excitation of ultraviolet light, which due to the T-4(1)((4)G)-(6)A(1)(S-6) transition of Mn2+ ions. Also it is observed that there exists energy transfer between the Zn2GeO4 host lattice and the activator (Mn2+). Under excitation of low-voltage electron beams, Zn2GeO4:Mn2+ shows strong green emission band dominating at 535 nm, corresponding to the T-4(1)((4)G)-(6)A(1)(S-6) emission of Mn2+ ions. The emission intensity and chromaticity coordinates of Zn2GeO4:Mn2+ as a function of accelerating voltage and the filament current were also investigated.