A new method of improvement of efficiency of silicon solar cells (SC) with structure of Al/tunneling thin SiOx/p-Si with induced inversion layer (MIS/IL) during their operation in solar modules structure has been presented. The method proposes modification of joining of the SC into modules as well as their photovoltaic properties improvement by means of external electrical bias. A mechanism of the reverse bias influence on structural parameters of the MIS/IL SC was studied theoretically. Relations expressing functional dependence of the MIS/IL structure parameters, and output electrical characteristics of SC on its base as function of the bias voltage value were obtained. Results of numerical calculations demonstrating efficiency of use of reverse electrical bias in the range from 0 to 0.6 V to increase the efficiency of the MIS/IL SC are presented. The method of external impact proposed has been compared with methods using technological aspects of silicon MIS/IL structures improvement.