Search

Abstract: Single-phase broad-band red-emitting Ca3Si2O7:Eu2+ phosphors, with photoluminescence features that qualify them as candidates for white light-emitting diodes applications, were successfully synthesized via a modified solid-state reaction method that employed H3BO3 as a flux. The phosphors produced have an intense broad red emission band, with a peak at 603nm, a full width at half maximum of 110nm, and color coordinates of (0.550, 0.438). Concentration quenching occurred at 0.01mol Eu2+. The discussion of the results shows that Eu2+ ions should be accommodated at the Ca-sites of the lattice, dipole–dipole interactions should predominantly govern the energy transfer mechanism among them, and the critical distance between them is ∼31Å. [Copyright &y& Elsevier]

Abstract: Ce3+/Eu2+ co-doped Li2SrSiO4 phosphor yields two emission bands consisted of blue and yellow components, which shows great potential as single host white phosphor for white LEDs. Effective energy transfer occurs in Ce3+/Eu2+ co-doped Li2SrSiO4 due to large spectral overlap between the emission of Ce3+ and excitation of Eu2+. Co-doping of Ce3+ enhances the emission intensity of Eu2+ greatly by transferring its excitation energy to Eu2+. The Ce3+ →Eu2+ energy transfer, thoroughly investigated by their absorption, excitation and photoluminescence decay behaviors, is demonstrated to be in the mechanism of electric dipole–dipole interaction. [Copyright &y& Elsevier]