Estimation of Judd-Ofelt Parameters for Eu³⁺-Doped Ca₃B₂O₆, Ca₂Al₂O₅, and Sr₃SiO₄Cl₆ Host Materials

The Judd-Ofelt (JO) parameters have remarkable importance for luminescent materials, which are estimated using emission and absorption spectra. In this work, JO parameters were estimated for Eu³⁺-doped Ca₃B₂O₆, Ca₂Al₂O₅, and Sr₃SiO₄Cl₆ host materials. The observed emission spectra and estimated JO parameters show that the structural environment of all the host matrices around the Eu³⁺ ions are centrosymmetric in nature. The effect of the concentration of Eu³⁺ ions in all three host matrices was investigated. The radiative transition probability (A_λ) for the ⁵D₀ → ⁷F₂ transition is greater than for the ⁵D₀ → ⁷F₁ transition for all Ca₃B₂O₆, Ca₂Al₂O₅, and Sr₃SiO₄Cl₆ host matrices. Further, the estimated branching ratio (β) for the ⁵D₀ → ⁷F₁ transition was closer to 45%, and for the ⁵D₀ → ⁷F₂ transition (in the range of 50–60%) was higher compared to the previous transition. Also, a comparison of barycentric estimated values showed that the peak position did not change significantly for the mentioned host matrices. The estimated values clearly indicate that the JO parameters are mostly properties of rare-earth-doped ions. Further, the values clearly suggest that the phosphors are candidates for laser system and light-emitting diode applications.