Luminescence behavior of Er 3+ ions in glass–ceramics containing CaF 2 nanocrystals

Abstract

The upconversion luminescence and near infrared luminescence of the Er 3+ ions in transparent oxyfluoride glass–ceramics containing CaF 2 nanocrystals have been investigated. The formation of CaF 2 nanocrystals in the glass–ceramics was confirmed by XRD. The oscillator strengths for several transitions of the Er 3+ ions in the glass and glass–ceramics have been obtained and then the Judd–Ofelt parameters were calculated. The split near infrared emission peaks of the Er 3+ ions in the glass–ceramics can be observed because the Er 3+ ions have been incorporated into crystalline environment of the CaF 2 nanocrystals. The upconversion luminescence intensity of Er 3+ ions in the glass–ceramics increased significantly with increasing heat treated time. The transition mechanism of the upconversion luminescence has been ascribed to a two-photon absorption process.