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 β-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 (3P1–1S0). 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.