Experimental and Theoretical Investigations on the Picosecond Deactivation Process of Excited F‐Centres in KCl

Abstract The deactivation behaviour of optically excited F‐centres in KCl is investigated for the first time by picosecond laser spectroscopy. It is found, that a certain portion of them returns to the ground state during 20 to 150 ps. This fast deactivation process, which depends on the F‐center concentration and the coloration method, can be explained by a model based on energy transfer between excited F‐centres, whereby an inhomogeneous spatial distribution can be taken into account. The critical transfer distance is observed to be R0 = (106 ± 15) Å. Quantitative characteristic results about the inhomogeneous spatial distribution of the F‐centres are presented.