Influence of PbO content on the glass forming ability, crystallization, electrical, UV–Vis. and photoluminescence spectroscopy properties of LiF.PbO system

Abstract

New glass samples were synthesized from the binary system LiF. PbO with different ratiosby the traditional melt-quenching technique. The corresponding glass-ceramics were formed by heat treating the prepared glasses. Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Transmission electron microscope (TEM) were employed to study the structure of the samples; while characterization of the glass and glass-ceramics were studied using photoluminescence (PL) spectral analysis, electrical, UV–Visible absorption, optical band gap and hardness measurements. The ability to form glass was increased with increase PbO content (1LiF:≥5PbO). Tetragonal and orthorhombic PbO, orthorhombic and monoclinic Pb2O3, α-PbF2 and traces of both Li4PbO4, PbO1.37 were crystallized under specific heat-treatment circumstances as identified by XRD analysis. The crystal size decreased with increasing the PbO content; it reaches ∼15 nm in case of 10 Pb. PL revealed concentration quenching in glass with 10 Pb, a red shift and enhancement of bands intensity were observed with decrease λex, increase heat-treatment temperature and increase PbO concentration. The UV–Visible absorption elucidated that the cutoff wavelength (λ) was shifted toward lower wavelength (blue shift) by increasing PbO content and the values of optical band gap energies recorded 2.69, 2.66 and 2.72 eV for LiF·5PbO, LiF·8PbO, and LiF·10PbO, respectively. The electrical properties recorded conductivity ∼1.2 × 10−6 S m−1 and dielectric constant ∼ 46.8. These characteristics suggests that, the prepared materials exhibited semiconducting and photoluminescence behavior nominated it to be utilized in solar cell applications.