Radiative Lifetimes of Excited Defect Centers in Sodium Fluoride.
ARMY MISSILE RESEARCH AND DEVELOPMENT COMMAND REDSTONE ARSENAL AL TECHNOLOGY LAB
Pagination or Media Count:
The luminescent decay time constants of F and 312 centers in NaF have been measured to be 65 or - 5 nsec at 78K for the F center and 19 or - 2 nsec at 78K and 290K for the 312 center. For controlled individual center density values of approximately 2 x 10 to the 16th power centers per cc to approximately 6 x 10 to the 14th power centers per cc in each of the samples, the luminescent decay time was found not to vary. The quantum efficiency of the F center was measured to be 6 or - 3 at 78K with a temperature dependent activation energy of 10 or - 4 x .001 eV, and the quantum efficiency of the 312 center was measured to be near 100 at both 78K and 290K. This high quantum efficiency for the 312 center allows the interpretation of its measured luminescent decay time as the radiative lifetime. The radiative decay time of the F center was calculated to be 1 or - 0.4 microsec. Author