High-temperature treatment of films on the glass substrates creates composite films of main materials and dielectric phase in the oxygen-containing medium. In this case the concentration of free holes in the vicinity of the crystallites surface decreases and photoluminescence of films grows up. Annealing in iodide vapor leads to the appearance of photoconductivity and to sharp intensification of photoluminescence of films. The effects are explained by inversion of surface conductivity in PbSe crystallites because of formation of localized states having the donor character.