Ni2+-doped new silicate glass-ceramics for broadband near infrared luminescence

Abstract

The new composite transparent spinel silicate glass–ceramics containing Ni2+-doped ZnGa2O4 and solid solution MgxZn1−xGa2O4 nanocrystals were fabricated by in situ controlled crystallization method. After heat treatment, the crystal phase content of ZnGa2O4 increase with increasing heat treatment temperature, and the Mg2+ ions could enter the crystal lattice of ZnGa2O4 to replace the Zn2+ ions and form a new solid solution MgxZn1−xGa2O4. The coordination environment of Ni2+ was changed from tetrahedral in glasses to octahedral sites in glass ceramics. The super-broadband infrared luminescence with full width at half maximum (FWHM) of about 400 nm overing 1.1–1.7 μm wavelength region and fluorescent lifetime of about 480 μs were observed from the glass ceramics containing MgxZn1−xGa2O4 nanocrystals. It is probably due to the variety of solid solution structure making Ni2+ ions enter two different octahedral sites. At the same time, the impact of heat treatment temperature and the concentration of NiO on peak position and intensity were also discussed. The results demonstrate that the method presented may be an effective way to fabricate super-broadband optical amplifiers and tunable lasers.