Crystal Structure–Photoluminescence Correlations in Ce3+-Doped Ca2ZnSi2O7phosphors

Abstract

In this work, Ce3+-doped Ca2-x ZnSi2O7:xCe3+ phosphors were prepared by the solid-state reaction in air. The crystal structure and photoluminescence properties of the prepared phosphors were investigated. All the prepared samples formed the tetragonal crystal structure. XRD Rietveld refinement was performed to retrieve a detailed crystal structure of the Ca2-x ZnSi2O7:xCe3+ phosphors. The lattice parameters a and c increased with increasing Ce3+concentration. The lattice parameters a and c of the Ca1.996ZnSi2O7: 0.004Ce3+ phosphor were 7.825 Å and 5.015 Å, respectively. The Ca2-x ZnSi2O7:xCe3+ phosphors showed strong and asymmetric bands covering the 415 to 650 nm range, which were attributed to the transitions of Ce3+ ions from the 5d excited state to the 2F5/2 and 2F7/2 ground states. The emission intensity increased with increasing Ce3+concentration up to x = 0.012. The dipole-dipole interaction was responsible for the concentration quenching. The CIE coordinate (x, y) was located in the blue spectral region. These results indicate that the prepared Ca2-x ZnSi2O7:xCe3+ phosphors can serve as an efficient blue phosphor in the white light emitting diodes.