Optimizing the White Light Emission of Pr³⁺ Activated SrCeO₃ Perovskite by Controlling the Excitation Wavelength for...

The current research illustrates excitation energy-triggered photoluminescent characteristics of Pr³⁺ions in SrCeO₃ providing a practical approach for developing high CRI wLED and its applications. SrCeO₃: xPr³⁺ (x = 0, 0.005, 0.01, 0.02, 0.03 wt) perovskites synthesized by fuel excess gel combustion method generate high CRI (~98) for wLED applications. Crystalline phosphors with orthorhombic structures having space group Pnma were confirmed by XRD. The unit cell volume expansion occurred with an increase in Pr³⁺ concentration was verified through the Rietveld refinement technique. Surface morphology, particle distribution, and size were observed via FE-SEM imaging, and detected a well-defined regular distorted spherical structure with average grain size 0.826 μm for Pr³⁺ doped SrCeO₃. Elemental mapping and EDS analysis identified the uniform distribution and elemental purity of SrCeO₃: 0.01 Pr³⁺. Further, the molecular vibrations and modes were analyzed from the Raman spectrum. Moreover, the average particle size assessed via TEM analysis was found to be ~83.2 nm, consistent with XRD analysis. UV-visible absorption spectra for optical energy-band gap analysis showed a decrease in band gap energy with an increase in Pr³⁺ concentration, realizing an effective energy transfer from Ce⁴⁺ to Pr³⁺. PL measurements showed a huge variety of emission transitions, corresponding to excitations 290 nm, 321 nm, 373 nm, and 449 nm. The critical dopant concentration instigated by concentration quenching was 1 wt% Pr³⁺, ascribed to dipole-dipole interaction. The fluorescence lifetime of the optimal sample was 4.835 μs. Commission International de I'Eclairage (CIE) diagram exposes the white light emanation of SrCeO₃: Pr³⁺. Among which white light with high CRI (~98) and comparably low CCT (~6311 K) was obtained for SrCeO₃: 0.01 Pr³⁺ at 373 nm excitation. The obtained results recommend that SrCeO₃: Pr³⁺ perovskite as an efficient white phosphor for fabricating high-performance wLEDs.