Effect of BO ₃ ^3- ions on photoluminescence of CaMoO ₄ :Eu ³⁺ phosphor

A series of CaMoO ₄ -BO ₃ ^3- :Eu ³⁺ phosphors with different concentrations of Eu ³⁺ (0, 0.5, 1.0, 1.5, 2.0, and 2.5 mol. %) were prepared using the solid-state reaction method. The crystal structure, particle morphology, and photoluminescence (PL) were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry, ultraviolet-vis diffuse reflectance, and PL spectroscopy. The XRD patterns showed that CaMo O 4 - B O 3 3 -: E u 3 + phosphor consisted of a pure phase with a tetragonal structure. The introduction of BO ₃ ^3- ions did not affect the crystal structure of the CaMoO ₄ :Eu ³⁺ phosphors, but it slightly influenced the particle morphology and the peak intensity of the red PL from Eu ³⁺ . As confirmed from the FE-SEM data, the shapes and sizes of the particles were modified by the incorporation of BO ₃ ^3- ions. The bandgap was influenced by the incorporation of BiO ₃ ^3- and Eu ³⁺ as confirmed from the diffuse reflectance data. The PL intensity was dependent on the concentration of the Eu ³⁺ , and the red emission due to the f → f transitions of Eu ³⁺ was enhanced considerably by the incorporation of BO ₃ ^3- ions when the samples were excited at the wavelength of 395 nm using a monochromatized xenon lamp. The effect of BO ₃ ^3- ions on the PL intensity is discussed.