Effects of crystal field on photoluminescence properties of Ca2Al2SiO7:Eu2+ phosphors

A series of single-phased Ca2Al2SiO7:Eu2+ phosphors were synthesized by the solid-state reaction. Their structure and photoluminescence properties were investigated by the X-ray powder diffraction (XRD) and excitation and emission spectra in detail. The emission spectra of Ca2Al2SiO7:Eu2+ phosphors consisted of blue and green band located at 419 and 542 nm, respectively. The relative intensities of the blue and green emission changed with Eu2+ concentration and were sensitive to the excitation wavelength. The unique photoluminescence property originated from the 4f7→4f65d transition of Eu2+ at different energy levels, on which the effect of the crystal field strength was considered to be tailed by adjusting the host composition.