Enhanced photoluminescence of SiO2 coated CaTiO3:Dy3+,Li+ nanophosphors for white light emitting diodes

Abstract

Systematic analysis of SiO2@CaTiO3:Dy3+(3 mol %):Li+(0.25–1 mol %) core shell nanoparticles (C–S NPs) were carried out. CaTiO3:Dy3+(3 mol %), Li+(0.25–1 mol %) NPs were prepared using low temperature solution combustion method. C–S structured samples were synthesized using SiO2 in equal weight quantities. All samples were characterised by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) in order to study and compare its structural properties. Photoluminescence (PL) properties of uncoated and SiO2 coated samples were studied in detail and optimum luminescence behaviour was investigated. Higher luminescence intensity is observed for codoped CaTiO3:Dy3+(3 mol %):Li+(0.5 mol %) sample. Further enhancement was observed in SiO2@CaTiO3:Dy3+:Li+ structured nanoparticles. Emission spectra of SiO2@CaTiO3:Dy3+(3 mol %):Li +(0.25–1.0 mol %) C–S nanophosphors exhibit white emission dominated by 4F9/2 → 6H13/2 (570 nm) transition of Dy3+ ions under. All the results suggested that the present material provides a platform for fabricating new functional materials which can be applied in the field of wLEDs and solid state display applications.