The possibility of using electroluminescence to study Si–Ta₂O₅ and Si–SiO₂–Ta₂O₅ structures and obtain information on the electronic structure of the Ta₂O₅ layer and on the properties of the SiO₂–Ta₂O₅ interface is shows. A model of the electronic structure of the Ta₂O₅ layer formed by molecular layer deposition is proposed, which explains the spectral distribution of luminescence independently of the method of its excitation. It is shown that the formation of a Ta₂O₅ layer on the surface of thermally oxidized silicon is accompanied by transformation in the near-surface SiO₂ layer and by quenching of the luminescence band in the spectral region of 650 nm.