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

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.