Green Zn3Al2Ge2O10: Mn2+ Phosphors: Solid-Phase Synthesis, Structure, and Luminescent Properties

Abstract Novel green phosphors Zn 3 Al 2 Ge 2 O 10 : Mn 2+ were successfully synthesised at high temperature under weak reducing atmosphere. X-ray diffraction results indicate that the samples have like-spinel structure. The morphology, chemical states, and the composition of the dopants in the host were analysed with high-resolution transmission electron microscopy, energy dispersive spectrum, high-angle annular dark-field, and X-ray photoelectron spectroscopic techniques. The photoluminescence spectra show that the emission peak is at 537 nm (under excitation at λ ex = 334 nm), which is the strong green emission resulting from the 4 T 1 ( 4 G)- 6 A 1 ( 6 S) transition of Mn 2+ ion. The full width at half maximum broadband of the strongest broad emission is about 50 nm. The Zn 3 Al 2 Ge 2 O 10 doped with 4 mol% Mn 2+ appears to have the highest emission intensity after thermal treatment at 1250 °C for 5 h. The CIE coordinates are x = 0.279, y = 0.625, corresponding to green region, and the decay time is 4.88 μs. The results indicate that the phosphors may be used as a trichromatic fluorescent material.