Structural properties and photoluminescence spectra of coloured LiF films on SiO2

Lithium fluoride films, about 2.6 mu m of thickness, were thermally evapora ted onto a 10 mu m thick SiO2 film grown on silicon [100] substrate. Colour ed stripes in the LiF films were created by low energy electron (12 keV) be am lithography. Intense photoluminescence (PL), extending from green to red in the visible spectral range, was measured at room temperature due to the presence of the laser active F-2 and F-3(+) colour centres. Atomic force m icroscopy (AFM) analysis was used to study the film morphology inside and o utside the irradiated areas. A confocal microscope was used to observe the surface layer of the film. (C) 1999 Elsevier Science B.V. All rights reserv ed.