Study of the electronic structure of Al(III) and Zn(II) complexes with organic ligands by quantum chemistry and photoelectron spectroscopy methods

Photoelectron spectra of aluminum complexes with 8-oxyquinoline (Alq ₃) and zinc complexes with N, N′-(o-phenylene)-bis(salicylidenediamine) (ZnSaloph) were measured on a photoelectron spectroscopy station at the Kurchatov Centre for Synchrotronic Radiation over the range of photon energies from 10 to 100 eV. Thin films of these compounds (∼20 nm thick) prepared by thermal evaporation onto glass substrates covered with transparent electroconductive layer of solid solution of tin and indium oxides (In₂O₃, SnO₂, ITO) were used as the objects of this study. The spectra of the valence band of these compounds and Al 2p level were measured. The data of quantum chemical calculations of the electronic structure obtained by the density functional theory are in good agreement with the experimental photoelectron spectra. Analysis of performance efficiency of the device was carried out on the basis of the results of calculation. This procedure does not result in decomposition of samples in the process of investigation and may be used for studying the electronic structure of coordination compounds with organic ligands in films.