Luminescence and radiative features of Gd2O3 modified and Pr3+ doped borate glass via energy transfer from Gd to Pr for blue- and UV-excited WLEDs

Abstract

We investigate the XRD, FTIR, structure variation factors, optical absorption, luminescence and radiative behaviors of mixed Gd₂O₃ in a 20Li₂O₃-30SrO-(49-x)B₂O₃-xGd₂O₃-1Pr₂O₃ glass. The Judde-Ofelt (J-O) analysis of the absorption spectra is performed to deduce intensity parameters. The refractive index and Ω_{λ = 2, 4, 6} values are employed to evaluate the branching ratios (β_R), and radiative transition probabilities (A_R) of Pr³⁺ luminescent states. At a wavelength of 444 nm for optical pumping, critical factors such as significant optical gain, and gain bandwidth in the ³P_o → ³H₄ transition for designing visible laser systems are estimated. The Gd³⁺ ions sensitize the Pr³⁺ ions through ET from their ⁶P_7/2 state to the ³P_{J = 2, 1, 0} states of Pr³⁺ ions. The extracted Commission Internationale de l'Éclairage (CIE), correlated color temperature (CCT) and color purity (CP) values from the luminescence spectra demonstrate the emission of white light. These results have implications for WLEDs and optical amplification.