Study of structural, luminescence and Judd-Ofelt calculations for Ce 3+ doped ZnS phosphors for display applications

This paper discusses the luminescence properties of novel Zn (1-x) S: x Ce 3+ ( x  = 0, 0.01, 0.02, 0.03, 0.1, 0.2 and 0.3) prepared via conventional solid-state reaction method at low temperature. The XRD results revealed that all synthesized phosphors have hexagonal structure. The strain was calculated using size-strain plot (SSP) method. The FTIR study identifies the various vibrational modes present in the synthesized phosphors. The structural and luminescence characteristics of the prepared samples were enhanced by Ce 3+ substitution. The optical band gap energies were found to be decreasing with Ce 3+ substitution. The optimal Ce 3+ content for superior blue emission is found to be  x   = 10 mol %. The blue emission supports the incorporation of Ce 3+ ions within the ZnS lattice, which is again confirmed by Ω 2, Judd-Ofelt intensity parameter. The high value of Ω 2 indicates the symmetry of site occupies of Ce 3+ ions are lower. The obtained critical distance of energy transfer between Ce 3+ ions is calculated to be 6.3095 Å, which implies that the exchange interaction mechanism is a multipolar exchange. The high efficiency, branching ratio, stimulated cross section and the optical parameters indicate that the prepared phosphor materials have efficient blue light emission for display applications.