Effect of carbon addition and TeO2 concentration on NIR luminescent characteristics of TeO2-doped soda-lime–silicate glasses

The effects of carbon addition and TeO2 concentration on the near-infrared (NIR) luminescent characteristics of Te-doped soda-lime–silicate glasses are investigated. Three absorption bands were detected in all glasses at around 330–380 nm, ∼430 nm and ∼630 nm, respectively. The last absorption band (∼630 nm) has been ascribed to 2Πg → 2Πu transition of Te2-. The broad NIR luminescence centered at 1200 nm was detected under the excitation of 974 nm laser diode except for glasses of lower carbon addition. The NIR luminescence was found to be strongly affected by melting atmosphere and TeO2 concentration. It is considered that the absorption band, ∼630 nm, is related strongly to the NIR luminescence of Te-doped soda-lime–silicate glasses. Consequently, it is suggested that the origin of NIR luminescence detected in Te-doped soda-lime–silicate glasses is likely to be caused by Te−2.