Properties ofFCenters in NaF

Abstract

A weak intensity emission, centered at 785 mμ, is identified as the $F$ photoluminescence in NaF. The temperature dependence of photoionization and photoluminescence of $F$ centers is investigated. Two thermal activation energies are found: $\Delta E_L=0.06\mathrm{}$ eV for the photoluminescence, and $\Delta E_1=0.12\mathrm{}$ eV for the photoionization efficiency. The nature of the quenching mechanism of the $F$ luminescence is discussed.