Synthesis and photoluminescent properties of Gd3O4Br:Er phosphors prepared by solid-state reaction method

Pure orthorhombic Gd₃O₄Br:Er³⁺ upconversion phosphors were synthesized by a solid-state reaction method and the structural properties of Gd₃O₄Br:Er³⁺ were investigated by X-ray diffraction; field emission scanning electron microscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. The results show that Gd₃O₄Br has low phonon cutoff energy, indicating that Gd₃O₄Br:Er³⁺may have high luminescent efficiency. Intense green (514–582 nm) and strong red (645–692 nm) upconverted luminescence of Gd₃O₄Br:Er³⁺ were observed under 980 nm laser excitation. The bright green emission is visible to the naked eyes even for 1 mW of the pump power (980 nm) for Gd₃O₄Br:Er³⁺ (0.1%) samples, indicating that Gd₃O₄Br:Er³⁺ may be used as upconversion phosphors.