Color tunable emission and energy transfer in LaSi3N5:Ce3+,Tb3+ phosphors for UV white LEDs†
Abstract
A series of new blue-green emitting LaSi3N5:Ce3+,Tb3+ phosphors were obtained through a high temperature solid-state method. The crystal structure, photoluminescence properties and energy transfer from Ce3+ to Tb3+ were investigated. The doped ions Ce3+ and Tb3+ were confirmed to occupy the same crystallographic sites as La3+ using a Rietveld structure refinement method. The emission spectra of these phosphors was composed of a blue emission band attributed to the d–f transition of Ce3+, together with several sharp lines ascribed to the emission of Tb3+ under UV light excitation. Thus a color tunable emission from blue to green was obtained via controlling the doping concentration of Tb3+. In addition, the mechanism of energy transfer, efficiency of energy transfer, chromaticity coordinates and thermal stability of these phosphors were investigated. The results indicated that the Ce3+,Tb3+ co-activated LaSi3N5 phosphors with color-tunable blue-green emission and high quantum efficiency may have potential for UV white LEDs.
- This article is part of the themed collection: RSC Advances Editors' collection: f Block Chemistry