Preparation and luminescent properties of sol–gel derived SiO2–B2O3:Tb glass films

Borosilicate glass films doped with rare-earths were deposited on glass substrates by using a simple sol–gel method. To avoid the undesirable precipitation due to the different hydrolysis rates between silicon and boron alkoxides, two solutions were used for dip-coating separately. One solution consisted of silicon tetraethoxide, ethanol, water and terbium nitrate as the Tb dopant. Another consisted of triethyl borate. Layer-by-layer deposition was applied by dipping into these solutions in sequence. The luminescent properties of Tb3+ were investigated for the borosilicate samples in relation to the firing effect. After firing at 900 °C, a remarkable increase (≈8 times) of the Tb3+-ion luminescence was observed for the borosilicate samples, while the silicate sample showed about 3 times increase in luminescence intensity. The boron addition of as low as 1 mol% of B2O3 was found to be very effective in increasing the Tb3+ luminescence intensity.