Synthesis, luminescent properties and theoretical calculations of novel orange-red-emitting Ca2Y8(SiO4)(6)O-2:Sm3+ phosphors for white light emitting diodes

Chen, Chun-Ting; Lin, Tzu-Jen; Molokeev, Maxim S.; Liu, Wei-Ren DYES AND PIGMENTS, 150 121-129; 10.1016/j.dyepig.2017.10.047 MAR 2018

The novel orange-red-emitting Ca2Y8(SiO4)6O2:Sm3+ phosphors (CYSO:Sm3+) were synthesized via conventional a solid state reaction. The crystal structure and atomic coordinates of CYSO:Sm3+ was characterized by Rietveld refinement. Luminesce properties of as-synthesized CYSO:Sm3+ phosphors are carried out by PL/PLE, decay life time, thermal quenching as well as reflectance spectrometer and LED fabrications. The results indicates that composition-optimized CYSO:1%Sm3+ exhibits orange-red emission peaks located on 564, 601, 608 and 648 nm attributed to the transitions of 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2, respectively. The decay lifetime of CYSO:Sm3+ phosphors was in the range of 0.37–1.10 ms. The temperature-dependent photoluminescence is decreased to 80% from room temperature to 150 °C, which is superior to that of commercial red phsophpr-Y2O3:Eu3+. The results of LED fabrication by combing 405 chips and blue/green phosphors are demonstrated in this study. Finally, from viewpoint of theoretical calculations, band structure and density of state for CYSO and CYSO:Sm3+ are studied by first principles calculations. All the results indicate that CYSO:Sm3+ phosphors could be a potential material for white light-emitting diodes.