Origin Of Near-Ir Luminescence In Bi2o3-Geo2 And Bi2o3-Sio2 Glasses: First-Principle Study

First-principle study of bismuth-related oxygen-deficient centers (= Bi center dot center dot center dot Ge equivalent to, = Bi center dot center dot center dot Si equivalent to, and = Bi center dot center dot center dot Bi = oxygen vacancies) in Bi2O3-GeO2, Bi2O3-SiO2, Bi2O3-Al2O3-GeO2, and Bi2O3-Al2O3-SiO2 hosts is performed. A comparison of the calculation results with the experimental emission and excitation spectra of IR luminescence suggests that luminescence in the 1.2-1.3 mu m and 1.8-3.0 mu m ranges in Bi2O3-GeO2 glasses and crystals is likely caused by = Bi center dot center dot center dot Ge equivalent to and = Bi center dot center dot center dot Bi = centers, respectively, and the luminescence near 1.1 mu m in Bi2O3-Al2O3-GeO2 glasses and crystals may be caused by = Bi center dot center dot center dot Ge equivalent to center with (AlO4)(-) center in the second coordination shell of Ge atom. (C) 2014 Optical Society of America