Broadband NIR emission from transparent fluorosilicate glass-ceramics containing Rb2SiF6:Ni2+ nanocrystals

Ni2+-doped fluorosilicate glass-ceramics with broadband emission have been prepared. The structural characterizations show that Rb2SiF6 nanocrystals separated from the glassy phase in the sample with a composition of RbF-ZnF2-SiO2:Ni2+. Moreover, the obtained Rb2SiF6 nanocrystals with the size of around 30 nm rely on stringent control of the heat-treatment temperatures. The experimental data reveal that Ni2+ selectively incorporates into the cubic Rb2SiF6 nanocrystals and locates at a typical 6F-coordinated octahedra. Meanwhile, a broadband emission in the important NIR range from 1200 to 2000 nm appears with the precipitation of Rb2SiF6 nanocrystals. The emission can be ascribed to the T-3(2g)(F-3) -> (3)A(2g)(F-3) transition of octahedral Ni2+ incorporated in the Rb2SiF6 crystalline phase. The Rb2SiF6:Ni2+ containing glass-ceramics provide an innovative choice for the development of photonic glasses with broadband emission.