Synthesis and Spectroscopic Investigations of Sm³⁺ Activated ZrO₂ and Na₂ZrO₃ as Warm Light Phosphors

In this work, we investigate how the structural and optical characteristics of ZrO₂ and Na₂ZrO₃ are influenced by Sm³⁺ ion doping. Urea-assisted combustion approach is employed by varying the molar concentration of Sm³⁺ ions in both the host lattices. XRD pattern revealed the monoclinic crystal system for both samples. XPS investigation has been examined to acquire the chemical information of the samples. FESEM is used to identify the morphology of the samples. The optimum molar concentrations of Sm³⁺ doped ZrO₂ and Na₂ZrO₃ phosphors, as per photoluminescence (PL) findings, are 1.5 mol% and 2 mol%, respectively. CIE coordinates of ZrO₂:Sm³⁺ and Na₂ZrO₃:Sm³⁺ are found to be (x = 0.59, y = 0.41) and (x = 0.61, y = 0.39) that corresponds to the amber region of color gamut. The optical bandgap for the synthesized samples is estimated using the UV-Vis diffuse reflectance spectra and the obtained values for the optimal concentration of dopant (Sm³⁺) in the ZrO₂ and Na₂ZrO₃ samples are 4.61 and 4.94 eV, respectively. The findings of the study reveal that the synthesized phosphors may be utilized as warm light phosphors and be a promising candidate for amber light-emitting diodes (LEDs).