Concentration-dependent physical, optical, and photoluminescence features of Pr3+-doped borate glasses

Lanthanum barium borate glasses doped with praseodymium were fabricated by a melt-quenching process, to study the effect of Pr2O3 on their properties. The addition of Pr2O3 in glass increases its density, molar volume, and refractive index. XRD confirms an amorphous nature of glass network, and XANES approves the praseodymium character as Pr3+ oxidation state in glass. Glasses absorb photons in ultraviolet and near-infrared region by the Pr3+ transitions from H-3(4) ground state. The photoluminescence spectra of glasses exhibit the strongest emission at 602 nm (D-1(2) -> H-3(4)) under 442 nm excitation (H-3(4) -> P-3(2)). The optimal 0.5 mol% Pr2O3-doped glass possesses the highest emission intensity due to the concentration quenching effect. Judd-Ofelt theory was used to determine the Pr3+ site environment in glass and its dominant stimulated emission. Strong orange emission of this glass is suitable for orange solid-state lasers, LEDs, and emitting devices.