Local structure, spectroscopic properties and intrinsic photoluminescence of the un-doped lead-containing glasses of different composition

Abstract

The X-ray diffraction, infrared transmission, optical absorption, photoluminescence spectra and decay kinetics of a series of un-doped Pb-containing glasses with compositions of 0.4PbO–0.6GeO2, 0.6PbO–0.4SiO2, 0.7PbO–0.3B2O3, and 0.54PbO–0.34B2O3–0.12GeO2 were studied. Average interatomic distances and coordination numbers for main structural units GeO4, SiO4, BO4, BO3, and PbOn (n = 3 – 6) in all studied glasses were derived from radial distribution functions. The 0.4PbO–0.6GeO2 and 0.54PbO–0.34B2O3–0.12GeO2 glasses upon UV photoexcitation show intense broad emission bands with maxima at 478 and 543 nm, respectively, and weaker broad band with peak about 610 nm. Based on luminescence decay kinetics analysis were proposed fast (band-to-band recombination) and slow (recombination with participation of point defects) mechanisms of intrinsic luminescence in the 0.4PbO–0.6GeO2 and 0.54PbO–0.34B2O3–0.12GeO2 glasses. The 0.6PbO–0.4SiO2 and 0.7PbO–0.3B2O3 glasses under UV – violet photoexcitation reveal only broad emission band with a maximum at 599 and 593 nm, respectively, caused by the band-to-band fast recombination mechanism.