To model the active layer in the hetero-junction solar cells, the C60, C70, PC60BM, PCBDAN fullerenes as acceptor, and (OS)n=1) oligoselenophenes as donor were considered. The (OS)n=14/C60, (OS)n=14/C70, (OS)n=14/PC60BM, and (OS)n=14/PCBDAN blends as a model of the active layer in the BHJ solar cell were chosen, and the optoelectronic properties were studied. The calculated efficiency of these ...