Effective conversion of solar energy into electricity is possible due to solar cells (SC) that match not only the terms of reliability but also relatively simple techniques of their manufacture. One type of a structure that largely fits into the above-mentioned methods is based on the ITO/n-Si heterojunctions made by spray-pyrolysis instead of using vacuum technologies.   The main purpose of this paper is to investigate the influence of methods of the surface treatment of silicon wafer on load characteristics of ITO/n-Si obtained by spray pyrolysis.   ITO/n-Si structures were obtained by spraying the solution of the ethanol mixture of indium and tin salts on the surface of Si wafers with electronic conductivity, the crystallographic orientation (100) and a charge carrier concentration of 1015cm-3. A pre-treatment of the absorbing layer is performed in the following order: degreasing the solution for 15-20 minutes in NH3: H2O2: H2O (1: 1: 8) heated to a temperature of 70-80°C; deoxidation of the Si surface in the hydrofluoric acid for 2 minutes; rinsing the wafer in distilled water and kept at a temperature of 450°C for 10 minutes. This annealing leads to the formation of the SiO2 layer on the Si wafer surface with a thickness of 1…2nm.   The investigation of the I-U characteristics at various temperatures allowed the determination of the mechanism of transition of charge carriers through the potential barrier of the ITO/n-Si structure, which has been shown to be of a tunneling-recombination, which corresponds to the model described in [1]. From the mathematical point of view, these processes are described by the equation: J = Jo exp(BT)exp(AV) where A and B are constants that do not depend on temperature and voltage, respectively.  The numerical value of the physical size of A is equal to 15 V-1 and that of B is 0.045 K-1. The characteristic of the transport mechanism in this case is the following: under conditions that create flat bands, it does not change as opposed to [1]. The observed fact could be accounted for by the presence of a thin SiO2 layer on the ITO/Si structure interface.  From investigations of a load characteristic of the Cu/ITO/SiOx/n-Si/Cu structure measured under standard conditions (AM1.5, 100mW/cm2, 25°C), the following parameters to CS manufactured by the technology described above were obtained: Isc = 32.49 mA/cm2 Ucd = 606mV, FF = 0.70 and Eff.= 13.8%.     The technological conditions proposed here for the fabrication of the structures of the CS type allows the elimination of traditional etching, which facilitates the process of obtaining the Cu/ITO/SiOx/n-Si/Cu SC and makes it possible to achieve a conversion efficiency of about 14%.   This research was performed in the frame of the Institutional Project CSSDT 15.817.02.04A