Judd-Ofelt analysis and luminescence behavior of Er3+ ions in glass ceramics containing SrF2 nanocrystals

The upconversion luminescence and near infrared luminescence of the Er3+ ions in transparent oxyfluoride glass ceramics containing SrF2 nanocrystals have been investigated. The formation of SrF2 nanocrystals in the glass ceramics was confirmed by x-ray diffraction. The oscillator strengths for several transitions of the Er3+ ions in the glass and glass ceramics have been obtained and then the Judd-Ofelt parameters were determined. The split near infrared emission peaks of the Er3+ ions in the glass ceramics can be observed because the Er3+ ions have been incorporated into crystalline environment of the SrF2 nanocrystals. The upconversion luminescence intensity of Er3+ ions in the glass ceramics increased significantly with the increasing crystallization time. The transition mechanisms of the green and red upconversion luminescence have been ascribed to two-photon process and the blue upconversion luminescence to three-photon process.