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

Abstract

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 0.826μm 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 ~83.2nm, 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 290nm, 321nm, 373nm, and 449nm. 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 4.835μs. 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 (~6311K) was obtained for SrCeO3: 0.01 Pr3+ at 373nm excitation. The obtained results recommend that SrCeO3: Pr3+ perovskite as an efficient white phosphor for fabricating high-performance wLEDs.