Electron injection effect in In2O3 and SnO2 nanocrystals modified by ruthenium heteroleptic complexes

Abstract

In this work, the optical characteristics and conductivity under photoactivation with visible light of hybrids based on nanocrystalline SnO₂ or In₂O₃ semiconductor matrixes and heteroleptic Ru(II) complexes were studied. The heteroleptic Ru(II) complexes were prepared based on 1H-imidazo[4,5-f][1,10]phenanthroline and 2,2′-bipyridine ligands. Nanocrystalline semiconductor oxides were obtained by chemical precipitation with subsequent thermal annealing and characterized by XRD, SEM and single-point BET methods. The heteroleptic Ru(II) complexes as well as hybrid materials were characterized by time-resolved luminescence and X-ray photoelectron spectroscopy. The results showed that the surface modification of SnO₂ nanoparticles with heteroleptic ruthenium complexes led to an increase in conductivity upon irradiation with light appropriate for absorption by organometallic complexes. In the case of In₂O₃, the deposition of Ru(II) complexes resulted in a decrease in conductivity, apparently due to the special structure of the surface layer of the semiconductor.