Optical and structural studies of some zinc calcium borate glasses for optoelectronic device applications

Samples of bismuth borate glasses were prepared by the melt-quenching method, following the molar ratio formula [(58.4–2x) mol% B₂O₃ + (18.8 + x) mol% ZnO + (18.8 + x) mol% CaO + 4 mol% Bi₂O₃)], where x = 0, 2, 4, 6, and 8 and equal concentrations of zinc oxide and calcium oxide were incorporated into the glass matrix. The structural analysis of the prepared materials was characterized using X-ray diffraction measurements, where each sample showed highly homogenous glassy nature. Deconvolution of X-ray diffraction data was employed to separate unresolved bands, and results manifested the existence of two micro-nucleating agents at 2θ values about 30° and 50°. Optical and optoelectronic properties of the present glasses were assessed using the UV optical absorption. Introducing both zinc and calcium oxides increased the glass transparency for electromagnetic radiation in the UV region. Additionally, values of Fermi energy, Urbach energy, optical conductivity, and the linear refractive index were decreased by the incorporation of both zinc and calcium oxides, while the quality factor was increased. Our results suggest the studied materials for optical filtering, optical switching, and optoelectronic device applications.