Synthesis, Characterization and Luminescence Investigation of Sm³⁺ Doped Na₃Bi(PO₄)₂ Phosphors for White Light Emitting Diodes

Abstract

The synthesis of the Na₃Bi(PO₄)₂: phosphor that has been activated by Sm³⁺ was accomplished by utilizing a wet-chemical reaction method. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) were all used to investigate the created Na₃Bi(PO₄)₂:Sm³⁺ phosphors. By utilizing the reflectance spectra of undoped Na₃Bi(PO₄)₂ and doped phosphors Na₃Bi(PO₄)₂:Sm³⁺, researchers have determined the presence of strong energy absorption bands that appear in the region of 200–300 nm. Upon the stimulation of photoluminescence at 404 nm, the doped Na₃Bi(PO₄)₂:Sm³⁺ phosphor exhibits a broad emission in the range of 400-600 nm, with a peak emission wavelength of 598 nm. In contrast, the phosphor Na₃Bi(PO₄)₂ that had been doped with Sm³⁺ had three exceptionally strong emission bands at around 564 nm, 598 nm, and 645 nm, respectively. The transitions that caused the emissions were as follows: ⁴G_5/2→ ⁶H_5/2 (green emission), ⁴G_5/2→⁶H_7/2 (orange emission), and ⁴G_5/2→⁶H_9/2 (red emission). It has been established that the CIE (Commission Internationale de l’Éclairage) coordinates for the sample are as follows: x = 0.2841 and y = 0.3459. According to these findings, there is the possibility that the Na₃Bi(PO₄)₂:Sm³⁺ phosphors that were synthesized have the potential to be used as a good option for white light emitting diodes and display devices.