Spectroscopic properties and intrinsic photoluminescence of the un-doped lead borate glasses

The EPR, optical absorption, transmission, and photoluminescence of un-doped glasses of the PbO-B2O3-GeO2-La2O3 and PbO-B2O3-SiO2-ZnO systems were studied. Optical band gaps and Urbach energies for both glasses have been evaluated from fundamental absorption edge analysis. The PbO-B2O3-GeO2-La2O3 glass upon UV photoexcitation shows broad emission, consisting of two intense overlapping bands peaked about 465 and 610 nm. Excitation spectrum of the PbO-B2O3-GeO2-La2O3 glass show intense band peaked at 351 nm at monitoring of emission band at 465 nm that characterised by fast kinetics. Luminescence decay curve for emission band at 610 nm, registered upon excitation at 357 nm, were best fitted by two-exponential approximation with lifetimes in microsecond range. In the PbO-B2O3-GeO2-La2O3 glass were proposed fast and slow recombination mechanisms for emission bands peaked about 465 and 610 nm. The PbO-B2O3-SiO2-ZnO glass under excitation at 419 nm reveals only broad emission band peaked at 593 nm that characterised by fast kinetics.

Automated summary

The optical properties of two undoped glass systems were studied, with PbO-B2O3-GeO2-La2O3 glass showing broad emission upon UV excitation, while PbO-B2O3-SiO2-ZnO glass revealing only a broad emission band.