First-principle study of the near-IR luminescence centers in Bi2O3-GeO2 andBi2O3-SiO2 glasses

TL;DR

This study uses first-principle calculations to identify the specific oxygen-deficient centers responsible for near-IR luminescence in various bismuth-doped glasses, correlating spectral properties with experimental data.

Contribution

It provides a detailed theoretical analysis linking specific oxygen vacancy centers to observed luminescence in bismuth-doped glasses, advancing understanding of their optical properties.

Findings

Luminescence at 1.2-1.3 μm is likely caused by =Bi...Ge≡ centers.

Luminescence at 1.8-3.0 μm is associated with =Bi...Bi= centers.

Near 1.1 μm luminescence may involve =Bi...Ge≡ centers with AlO4- in the second shell.

Abstract

First-principle study of bismuth-related oxygen-deficient centers ($=$Bi$\cdots$Ge$\equiv$, $=$Bi$\cdots$Si$\equiv$, and $=$Bi$\cdots$Bi$=$ oxygen vacancies) in Bi$_2$O$_3$-GeO$_2$, Bi$_2$O$_3$-SiO$_2$, Bi$_2$O$_3$-Al$_2$O$_3$-GeO$_2$, and Bi$_2$O$_3$-Al$_2$O$_3$-SiO$_2$ hosts is performed. A comparison of calculated spectral properties of the centers with the experimental data on luminescence emission and excitation spectra suggests that luminescence in the 1.2-1.3 $\mu$m and 1.8-3.0 $\mu$m ranges in Bi$_2$O$_3$-GeO$_2$ glasses and crystals is likely caused by $=$Bi$\cdots$Ge$\equiv$ and $=$Bi$\cdots$Bi$=$ centers, respectively, and the luminescence near 1.1 $\mu$m in Bi$_2$O$_3$-Al$_2$O$_3$-GeO$_2$ glasses and crystals may be caused by $=$Bi$\cdots$Ge$\equiv$ center with (AlO$_4$)$^-$ center in the second coordination shell of Ge atom.