Assessment of physical, structural, optical, photoluminescence and shielding properties of europium doped lead borate glasses

Abstract

In this work, the melt-quenching technique was employed to prepare lead borate glasses with varying amounts of Eu₂O₃. Various characterization approaches were used to investigate the physical, structural, optical, luminescence, and radiation-shielding properties of the developed glasses. The phase and structural compositions were confirmed by XRD and FTIR spectroscopy. It was found that as the Eu₂O₃ concentration increases, the density and refractive index also increase. The optical absorption spectra from 350 to 2300 cm⁻¹ show five optical transitions in UV–Vis-NIR range. The absorption spectra results were used to calculate the direct and indirect bandgaps. The excitation spectra of photoluminescence found eight excitation bands in which the highest intensity transition was observed at 395-nm (⁷F₀ → ⁵L₆) under λ_emi = 613-nm. To study emission spectra, the 395-nm excitation wavelength was used. Five emissions bands at 578, 590, 613, and 700-nm were also evidenced. The highest intensity was recorded at 613 nm corresponding to ⁵D₀ → ⁷F₂ transition. The color coordinate (x, y) in the CIE diagram demonstrates the red–orange emission. The decay analysis demonstrates that when the Eu³⁺ content increases, the lifetime decreases. The shielding characteristics were observed in the energy range of 70–120 keV of X-ray. The HVL results at 120 keV revealed that these glasses provide greater shielding than commercial, concrete, red brick, and X-ray windows. Based on these observations, the fabricated glass can be used in numerous photonic applications such as illuminating and as a radiation shielding material.