Effect of precursor types on the characteristics of the Pb-based glass powders prepared by spray pyrolysis

Lead (Pb)-based glass powders with a spherical shape and submicron size were directly prepared by spray pyrolysis using spray solutions with various types of Pb and silicon (Si) components. The glass powders formed by the spray solution with Pb chloride and tetraethyl orthosilicate (TEOS) precursors had a broad X-ray diffraction (XRD) peak at around 28° with small crystalline peaks. The powders had an impurity peak caused by chlorine in the EDX spectrum. However, the glass powder formed from the spray solutions that contained Pb nitrate and Pb acetate precursors had an amorphous phase, irrespective of the type of Si precursor. The dielectric layers formed from the glass powders obtained from the spray solutions with Pb nitrate and Pb acetate had a dense structure and high transmittance above 85%, irrespective of the type of Si precursor components. In contrast, the dielectric layer formed from the glass powders prepared from the spray solution with Pb chloride and TEOS had large voids in the layer and had low transmittance below 50% under the visible range.