Synthesis and photoluminescence properties of novel red-emitting Ca14Mg2(SiO4)8:Eu3+/Sm3+ phosphors

Novel red-emitting Eu3+, Sm3+ singly doped and co-doped Ca14Mg2(SiO4)8 phosphors were prepared by conventional solid- state reaction. Powder X-ray diffraction patterns were employed to confirm phase purity. Ca14Mg2(SiO4)8:Eu3+ phosphors exhibited intense red emission under 394 nm excitation and Ca14Mg2(SiO4)8:Sm3+ phosphors, excited at 405 nm, also showed strong red emitting at 602 nm. The concentration quenching mechanism of Ca14Mg2(SiO4)8:Eu3+ was dipole-dipole interaction, while that of Ca14Mg2(SiO4)8:Sm3+ was energy migration among nearest neighbor ions. The results indicated that Ca14Mg2(SiO4)8:Eu3+ and Ca14Mg2(SiO4)8:Sm3+ were promising red-emitting phosphors for WLEDs. Meanwhile, the effect of co-doping Sm3+ ions on photoluminescence properties of Ca14Mg2(SiO4)8:Eu3+ was studied and energy transfer from Sm3+ to Eu3+ was discovered in Eu3+, Sm3+ co-doped phosphors.

(a) A schematic diagram of energy transfer model from Sm3+ to Eu3+ ions; (b) CIE chromaticity coordinates of (3) CMSO: 0.50Eu3+ (λex=390 nm), CMSO:0.08Sm3+ (1) and CMSO:0.08Sm3+,0.30Eu3+ (λex=405 nm) (2)Figure optionsDownload as PowerPoint slide