Investigation of luminescence and optical absorption of K2LiAlF6 : Cr3+ single crystals

摘要

Photoluminescence, absorption and excitation spectra of K(2)LiAIF(6) single crystals doped with 1% of Cr3+ are presented. The nearinfrared photoluminescence observed at room temperature, 77 and 4 K are attributed to the zero-phonon spin-allowed T-4(2)(F-2) -> (4)A(2)(F-4) transition of Cr3+ octahedrally coordinated by F- ions. Lifetimes are obtained. The 4 K emission broad band was described in terms of normal modes of the octahedral complex [CrF6](3-). The Racah, crystal-field and Huang-Rhys parameters are calculated and the quantum efficiency and thermal quenching estimated and compared with Cr3+ properties in different environments. (c) 2006 Elsevier Inc. All rights reserved.