TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: (II) comprises inorganic nanocrystals semiconductors acceptors optionally coated by an organic layer, semiconductor nanowires and/or organic acceptors, preferably coated with an organic layer comprising polythiophenes and/or oligothiophenes. The semiconductor nanowires are made of silicon, arsenic-gallium, germanium, indium-phosphorus, cadmium-selenium and/or cadmium-tellurium.Preferred Composition: The composition in the voltaic cell is selected such as the external output of cell conversion is greater than or equal to 3%.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: (II) are derivatives of fullerene C60, fullerene C61, fullerene C70, carbon nanotubes and their derivatives, perylene and its derivatives, quinoxalines and/or tetracyanoquinodimethane, preferably 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)-C61.    TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The obtained mixture is deposited directly on a substrate without annealing. The nanofibrils are prepared by forming a solution of (I) in an organic solvent i.e. favoring the nanofibrils obtention. The solution formation is carried out by dissolution at a temperature higher than the ambient temperature, followed by a slow cooling until the ambient temperature. The nanofibrils are separated from non-associated (I) by centrifugation and/or filtration. The mixing is carried out under agitation. The material is deposited in single layer or multi-layer on the solid substrate.Preferred Components: The nanofibrils present at 25-93 wt.% of (I). The organic solvent is para-xylene or cyclohexanone, chlorobenzene and/or dichlorobenzene. (I) is polythiophenes, polythienylene-vinylenes, polyphenylenes, polyphenylenevinylenes, polyanilines and/or polyfluorenes e.g. poly(3-hexylthiophene) (preferred), poly(3-hexyloxythiophene), poly(2-methoxy-5-(2'-ethylhexyloxy) p-phenylenevinylene) and/or poly(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene-vinylene) or their derivatives. (I) is present in the polymeric composition at 0.5-2 wt.%. The solid substrate is glasses, conducting polymers and polymers covered with conducting oxide and glasses covered with a conducting layer. The conducting polymers are polyethylenedioxythiophene and/or polyaniline. EXAMPLE - 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)-C61 (PCBM) (made of electrons donor) was added in solid form to a solution of polymeric chains non-associated with poly(3-hexylthiophene) (P3HT) at 1 wt.% in para-xylene. The ratio of P3HT:PCBM was 1:1. The solution was heated under agitation at 70degreesC. During the process of dissolution, the solution was protected from the light and the ambient air, to avoid chemical oxidation and/or photo-oxidation of polymer. The obtained limpid solution was cooled until ambient temperature at a rate of 20degreesC/hour to obtain the nanofibrils.