Spectral and optical properties of Ruddlesden-Popper-type Ba3Zr2O7 phosphors doped with Eu3+ ion

This paper reports the spectroscopic investigation of Ba3Zr2O7 phosphors. A series of Ba3Zr2O7: Eu3+ with the different molar concentrations (0-4 mol.%) of europium (Eu3+) ion is synthesized by the solution combustion method. The synthesized powders are characterized systematically using X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and ultraviolet-visible spectroscopy. X-ray diffraction results indicate that the synthesized powder has a tetragonal crystal structure. X-ray photoelectron spectroscopy is used to study the elemental composition of the synthesized phosphor. Field emission scanning electron microscopy result reveals that non-uniform morphology is formed. Photoluminescence spectroscopy result shows several emission peaks due to electronic transitions of Eu3+ ion, and the dominant peak is observed at 613 nm due to electric dipole transition D-5(0) -> F-7(2). CIE coordinates of Eu3+-activated Ba3Zr2O7 phosphor is found to be (x = 0.64, y = 0.36) which gives bright red emission. The optical band gap of the phosphors is obtained from the diffuse reflectance spectrum and found in the range of 4.62-4.83 eV.