NOVELTY - 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 support surface, a composition comprising (I), (II) and a solvent-S capable of solvating (II) and (II) without chemically reacting with each other, and (b) removing the solvent-S in the resulting deposit produced on the support by evaporation.    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 support surface, a composition comprising (I), (II) and a solvent-S capable of solvating (II) and (II) without chemically reacting with each other, and (b) removing the solvent-S 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 higher boiling point to that of 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).    R1 = hydrocarbyl or heterohydrocarbyl, where the total number of carbon atoms in R is at least 2;    R, R2, R3a = alkyl;    n = 1 or 2; and    R3 = H or -C(O)-R.    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.