Аннотация:We investigate the effect of oxygen molecule adsorption on the photoluminescence of porous silicon films of different porosity. The experimental results are explained by the photosensitization of singlet oxygen generation due to the energy transfer from excitons confined in Si nanocrystals to O2 molecules adsorbed on the Si nanocrystal surface. The energy transfer time and photosensitization efficiency are found to depend on porosity of the samples. The singlet oxygen generation efficiency increases strongly for porous silicon with high (>80%) porosity.