Luminescence of Oxide Films Obtained by Atomic Layer Deposition

The possibilities of the luminescence method for studying Si–oxide and Si–SiO2–oxide structures have been demonstrated. A model of the electronic structure of Ta2O5 and TiO2 layers is proposed, which explains the shape of the spectral luminescence distribution independent of the excitation way. A comparison of the luminescence spectra of single oxide layers with the spectrum of Si–SiO2–oxide structures made it possible to draw conclusions about the interaction between layers during layered structure formation and estimate the band gap: 4.4 and 3.3 eV for Ta2O5 and TiO2, respectively. The formation of Ta2O5 on the SiO2 surface led to transformation in the SiO2 surface region, manifesting itself in weakening of the luminescence band at 1.9 eV and formation of defects (luminescence centers) in the vicinity of 3 eV. Synthesis of TiO2 on the surface of SiO2 was not accompanied by any changes in the luminescence spectra.