The optical behavior, of point defects which were created by low-energy electron beams, was studied in multi-layer KCl/LiF films which had been grown by thermal evaporation onto amorphous substrates at a constant temperature of between 30 and 350C. The surface morphology of the samples was determined by means of atomic force microscopy. Large concentrations of F and F-aggregate centers were produced, by 3 to 7keV electron irradiation, in both in KCl and LiF layers. By pumping the films with suitable Ar+ laser lines, the first measurements could be made of luminescence, in the far-infrared region, which was due to F2 and F3 centers in KCl, as well as the typical emissions from F2 and F3+ centers, in the visible region.

F.Somma, M.Cremona, R.M.Montereali, M.Passacantando, P.Picozzi, S.Santucci: Nuclear Instruments and Methods in Physics Research B, 1996, 116[1-4], 212-5