Impurity core-valence luminescence of Cs-doped alkali chlorides

摘要

The features of relaxation processes occurring in the outermost core states of Cs-doped alkali chlorides have been studied via the measurements of the impurity core-valence luminescence (CVL) emerging from radiative recombination of valence electrons with the loes created in 5pCs-core states. The emission spectrum shape is revealed to exhibit obvious influence of the lattice relaxation effects rsulting in thermal broadening of the emission band. Strong enhancement of the emission yield and inverse anticorrelaton between luminescence exitation and reflection spectra is reveraled in the region of impurity core excitons. On the other side, manifestation of usual anticorrelation of these spectra is detected in the host core exciton region. The surface quenching effects are anticipated to govern, to a great extent, the character of decay processes in the above energy regions. The correlation between impurity CVL yield spectra and decay time behaviour versus excitation energy is found to confirm the mentioned suggestion.