Solar cells fabricated on the basis of semiconductor-insulator-semiconductor (SIS) structures were obtained by deposition of transparent conductive ITO films onto silicon crystal substrates by spray pyrolisys technique. The obtained in such a way structures may be considered as Schottky diodes with a thin insulating SiO2 layer at the interface formed during the ITO layer deposition. The investigation of I-V characteristics shows that in n ITO/SiO2/nSi structures two mechanisms of the direct current flow are presented: (i) tunnelingrecombination at direct voltages of less than 0.3 V and (ii) over-barrier emission at voltages higher than 0.3 V. In the first case the direct current flow could be interpreted as multi-steps tunnel-recombination transitions of electrons from the silicon conduction band into ITO conduction band, the number of steps being about 100. In the second case the calculated from I-V characteristics height of the potential barrier at the ITO-Si interface is about 0.65-0.68eV.