Broadband NIR luminescence of Bi-doped Li2O-Al2O3-SiO2 glass-ceramics

Transparent Bi-doped Li2O-Al2O3-SiO2 (LAS) glass-ceramics are prepared by controlled nucleation and crystallization of glasses with TiO2 worked as nucleating agents. The presence of beta-eucryptite (LiAlSiO4) crystalline phase can be indicated by X-ray diffraction analyses. Enhanced near infrared luminescence in the range of 1000-1550 nm with FWHM over 270 nm is observed from Bi-doped LiAlSiO4 glass-ceramics compared with initial glass. Blue emission centered at 425 nm in glass and glass-ceramics could be ascribed to the emission band of the Bi3+ ions (P-3(1)-S-1(0)). Based on optical basicity theory, the broad infrared luminescence from the Bi-doped LAS glass and glass-ceramics can be derived from low valence Bi ions. The possible mechanism of the enhancement of near infrared (NIR) fluorescence is also discussed in this manuscript. (C) 2012 Elsevier B.V. All rights reserved.