Luminescence properties of Pr3+ and Bi3+ co-doped NaCaTiNbO6 phosphor for red-LEDs

Abstract

This paper investigates the photoluminescence properties of NaCaTiNbO6:Pr3+ and NaCaTiNbO6:Pr3+, Bi3+ phosphors. NaCaTiNbO6:Pr3+ and NaCaTiNbO6:Pr3+,Bi3+ powder were synthesized successfully by solid state reaction method. Phase purity was checked using X-ray powder diffractometry (XRD). The excitation and emission spectra were recorded to elucidate the photoluminescence properties of NaCaTiNbO6:Pr3+ and NaCaTiNbO6:Pr3+,Bi3+. Furthermore, fluorescence lifetime measurements were performed. The excitation spectra of NaCaTiNbO6:Pr3+ show a main band centered at around 357 nm. The luminescence spectra of NaCaTiNbO6:Pr3+ exhibit a red emission peak at 615 nm from the 1D2 → 3H4 transition of Pr3+ ions. With the introduction of the Bi3+ ion into NaCaTiNbO6:Pr3+, the luminescence intensity is enhanced nearly two times. Meanwhile, the absorption band edge of NaCaTiNbO6:Pr3+ is shifted from 380 to 420 nm. Thus, this study shows that the red phosphor NaCaTiNbO6:Pr3+ incorporated with Bi3+ is advantageous for light-emitting diode applications.