Prototypes of organic photovoltaic cells based on the planar “subphthalocyanine/fullerene” heterojunction were fabricated using flexible polymeric substrates. Current-vs-voltage characteristics in the dark and under illumination were recorded and basic photovoltaic parameters were derived. It was shown that introduction of the (top) barrier layer composed of Alq3 molecules under the cathode significantly lowers the parasitic resistances in the cells, so that fill factor rises up to 55%. If the (bottom) buffer InClPc layer is deposited onto the anode (ITO), then the open circuit voltage of cells increases from 0.47 to 0.83 V. The highest power conversion efficiency was achieved in OPVC with both top and bottom interfacial layers (∼1%).