NOVELTY - Applying, on a whole or a part of a surface of a support, an organic coating with photovoltaic character, comprises (a) depositing, on support, a composition comprising P-type organic semiconductor compound (I), N-type organic semiconductor compound (II), and a solvent (S) capable of solvating (I) and (II) without chemically reacting with each other, and (b) removing the solvent (S) produced on the support by evaporation. The solvent (S) comprises a fraction F1 that comprises a solvent or a mixture of solvents (S1) and a fraction F2 that comprises e.g. pyrrolidin-2-one compound (A).    USE - The method is useful for applying an organic coating on a whole or a part of a surface of a support, which is useful in a photovoltaic cell (all claimed).    ADVANTAGE - The method is capable of simply applying the organic coating on the support surface with high stability and without performing annealing step thus economically manufacturing the photovoltaic cell with reduced weight and improved mechanical properties in an industrial manner.    DETAILED DESCRIPTION - Applying, on a whole or a part of a surface of a support, an organic coating with photovoltaic character based on a mixture of organic semiconductors including P-type organic semiconductor compound (I) and N-type organic semiconductor compound (II), comprises (a) depositing, on whole or part of the surface of the support, a composition comprising (I), (II) and a solvent (S) capable of solvating (I) and (II) without chemically reacting with each other, and (b) removing the solvent (S) present in the resulting deposit produced on the support by evaporation. The solvent (S) comprises: a fraction F1 that comprises a solvent or a mixture of solvents (S1) and is capable of solvating (I) and (II); and a fraction F2 that is miscible with the fraction F1, has a boiling point higher than the fraction F1, is a solvent or a mixture of solvents (S2) comprising a pyrrolidin-2-one compound of formula (A), a benzoic acid compound of formula (B) and an ester compound of formula (C) and is capable of solvating (I) and (II).    R3 = H or -C(O)-R;    R1, R2, R3a, R = alkyl; and    n = 1 or 2.    INDEPENDENT CLAIMS are included for:    (1) the composition comprising (I), (II) and the solvent (S); and    (2) the support provided with the coating obtained by the method.