p-n junction organic photovoltaics fabricated by all solution processing

► We prepared p-n junction organic photovoltaic cells by a solution processing. ► We compared the effects on p-n interface by different PCBM solvents. ► UV-Vis and AFM were conducted to study the morphology of active layer. ► We achieved the best device by processing with the lowest b.p. solvent for PCBM. ► The best device has a η 1.78%, Voc 0.44 V, Jsc 9.4 mA/cm2 and FF 0.43.