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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]

Abstract: Eu2+ and Mn2+ co-doped SrSi2O2N2 green-phosphors, with promising luminescent properties (examined by their powder diffuse reflection, photoluminescence excitation and emission spectra) suitable for UV converted white LEDs, were produced by high temperature solid-state reaction method. The produced materials exhibited intense broad absorption bands at 220–500nm and a broad emission band centered at ca. 530nm, attributed to 4f–5d transitions of Eu2+. The emission intensity of Eu2+ ions was greatly enhanced by introducing Mn2+ ions into SrSi2O2N2:Eu2+ due to the energy transfer from Mn2+ to Eu2+. The energy transfer probability from Mn2+ to Eu2+ depends strongly on the Mn2+ concentration, which is maximized at a Mn2+ concentration of 3mol%. It drastically decreases for higher concentrations. The results indicated that SrSi2O2N2:Eu2+, Mn2+ is a promising green-emitting phosphor for white-light emitting diodes with near-UV LED chips. [Copyright &y& Elsevier]