ORGANIC SOLAR CELLS.In this research we have designed electron donors D-π-A type containing two different π fragments to obtain naphthopyrrole (D-NPR-A) and naphthotiophene (D-NTP-A) derivatives, proposed for the use in organic bulk hetero-junction (BHJ) solar cells (OSCs).These derivatives were characterized by DFT and TD-DFT calculations.For all the electron donors the anchorage fragment was 2-methylenemalononitrile, while the chromophore fragment was spanned between diphenylamine, triphenylamine, thiophene.Properties affecting open-circuit photovoltage (V OC ) and short-circuit photocurrent (J SC ) from D-π-A type derivatives, such as geometric structure, frontier-molecular orbital energies, exciton driving force energy, natural bond orbital analysis, absorption spectra and light harvesting efficiency.Energy from HOMO and LUMO orbitals was discussed.Theoretical calculations from TD-DFT within Coulumb attenuation method CAM-B3LYP were able to predict excited state properties.The electron donors D-π-A type exhibit photoelectric conversion efficiency above 10%, being the naphthopyrrole derivatives (D-NPR-A) along with the [6,6]-phenyl-C61butyric acid methyl ester (PC 61 BM) the complexes with higher photoelectric properties, these complexes are proposed as photoactive materials in the construction of organic bulk hetero-junction solar cells.