Fabrication and luminescence of highly transparent C12A7:Tb^(3+)glass-ceramics via in-situ crystallization from aerodynamic levitation processed glasses

Rare earth doped 12CaO·7Al_(2)O_(3)(C12A7)glass-ceramics are one of attractive photonic materials due to their high transparency,high luminescent efficiency and eco-friendly nature.A series of C12A7 glasses with different Tb^(3+)doping concentrations was prepared by aerodynamic levitation method.The C12A7:Tb glass-ceramics were obtained via in-situ growth from the glasses with the identical chemical composition at 800℃.The microstructure observation demonstrates that the elemental distributions of Ca and Al are homogeneous in the glass-ceramics and the grain size of C12A7 is 4-70 nm.The in-line transmittance of glass-ceramics reaches as high as 82%at 1500 nm.The emission spectra of the C12A7:Tb glass-ceramics present characteristic Tb^(3+)emission peaks at 486 nm(^(5)D_(4)→^(7)F_6),541 nm(^(5)D_(4)→^(7)F_(5)),585 nm(^(5)D_(4)→^(7)F_(4))and 621 nm(^(5)D_(4)→^(7)F_(3)).The photolumine scence lifetime of C12A7:0.3%Tb glass-ceramic is 1.9 ms.Compared with the emission intensity of the glasses,that of the glass-ceramics increases due to the reducing in concentration of oxygen vacancy associated with network forming(NWF)cations.The highly transparent C12A7:Tb glass-ceramics may be a promising candidate for green light source in solid state lighting.