OPTICAL-PROPERTIES OF RBI THIN-FILMS GROWN FROM THE VAPOR-PHASE ONTO ALKALI-HALIDE AND QUARTZ SUBSTRATES

Rbf thin films with various thicknesses (20 similar to 2000 A) were gr own from the vapor phase onto sis substrates (RbBr, KBr, RbCl, NaCl, L iF and amorphous quartz), and characterized by the X-ray diffraction a nd by the optical spectra of the absorption and luminescence due to th e exciton transitions. The X-ray diffraction patterns showed that thes e RbI films were formed along the [001] direction normal to the substr ates. The optical spectra showed that the films grown on RbBr, KBr and RbCl remained a compressive strain due to the epitaxial growth, and t he films grown on LiF and quartz suffered a tensile strain due to the thermal stress between the films and substrates.