Photoluminescence and structural properties of NaBaBi₂[PO₄]₃ an Eulytite-type orthophosphate doped with Sm³⁺ as new orange-red emitting phosphors

A series of NaBaBi₂[PO₄]₃ doped with Sm³⁺ (NaBaBi_2−x[PO₄]₃:_xSm³⁺; x = 0.025, 0.05, 0.075, 0.1, 0.3, and 0.5) phosphors were prepared using a solid-state reaction method in the present study. To evaluate the crystallinity and purity of the phosphor, XRD analysis was employed. To establish the morphology and elemental analyses of the phosphors, FESEM with EDX was adopted. Investigations into the phosphors’ photoluminescence properties were extensively studied. The phosphor exuded many strong Sm³⁺ ion emission peaks, oriented at 563, 601, and 644 nm, respectively. The transition ⁴G_5/2 → ⁶H_7/2 of Sm³⁺ emits the most vivid orange-red light at 601 nm. According to Dexter’s hypothesis, quenching happens as a result of dipole–dipole interaction at x = 0.1, the ideal concentration of the Sm³⁺ doped phosphor. The critical distance for phosphor is 17.27 Å. It was established that the phosphor’s band gap is E_g = 4.25 eV for the undoped compound. The phosphors’ CIE chromaticity coordinate appears to have fallen in the orange-reddish spectral range. It’s possible to employ the Sm³⁺-doped phosphors found in NaBaBi₂[PO₄]₃ as orange-red phosphors in white light-emitting diodes.