The Influence of the Bismuth Concentration and Heat Treatment on the Properties of Bismuth-Containing High-Silica Glass: II. Luminescence Properties

Abstract

The luminescence properties of bismuth-containing high-silica glass obtained after impregnating matrices of porous glass in nitrate solutions of bismuth nitrate pentahydrate for 24–48 h followed by heat treatment in the range from 400 to 890°C are studied. It is found that the concentration of Bi(NO₃)₃ in the impregnating solution affects the content of bismuth in the synthesized samples stronger than the duration of the impregnation and the temperature of the heat treatment. It is established that all the samples studied in this work have blue-green luminescence (λ_em = 420–520 nm at λ_exc = 300 nm) caused by the presence of Bi³⁺ ions. When the concentration of bismuth in the samples is increased a long-wavelength shift of the luminescence band maximum is observed. When the heat treatment temperature is increased a shortwave shift is observed. A yellow-orange luminescence with the maximum in the λ_em range of 576–582 nm (λ_exc = 480 nm) caused by the presence of Bi²⁺ ions is observed for the samples with a high bismuth content (1.17–1.18 wt % of Bi₂O₃) heat-treated in air at ~700 and 750°C.