Judd–Ofelt analysis and the spectroscopic elucidation of β-BaB2O4:Eu3+ phosphors for optoelectronic applications

Abstract

We have used the solid-state reaction method to prepare Eu³⁺ (1, 1.5, 2, 2.5, and 3 mol%) doped β-BaB₂O₄ phosphors. Phase purity of the prepared phosphors was confirmed using X-ray diffraction (XRD) studies. Photoluminescence (PL) measurements using 395 nm excitation exhibited three intense peaks at 593 nm, 615 nm, 653 nm, and 702 nm, respectively, due to the ⁵D₀ → ⁷F_j (j = 0, 1, and 2) transitions. The PL emission intensity will increase up to 2 mol%, and thereafter, there will be a decline due to concentration quenching. Chromaticity analysis, along with correlated colour temperature (1796 K to 1976 K), confirmed the material's potential as a warm light emitter. Diffuse reflectance spectroscopy revealed a direct bandgap energy of 4.30 eV for the optimized sample. Finally, using Judd–Ofelt intensity parameters, the calculation of critical radiative parameters, including transition probability, lifetime, and branching ratio, was carried out. The results demonstrate the efficient luminescence and excellent colour stability of β-BaB₂O₄:Eu³⁺, highlighting its potential for optoelectronic applications.