NOVELTY - A photoactive composition (C1) with a high mobility of the electronic holes, comprises: at least one organic photoactive polymer; and at least one naphthalene diimide compound.    USE - As photoactive composition having high mobility of electronic holes, useful in construction of photovoltaic devices, such as photovoltaic cells, photovoltaic modules, solar cells, and solar modules; organic thin film transistors (OTFT), and organic field effect transistors (OFET) (claimed).    ADVANTAGE - The photoactive composition comprising organic photoactive polymer and naphthalene diimide compound (I) has high mobility of electronic holes, can more effectively transport charges to electrodes, and improves efficiency of materials used in photovoltaic devices. The composition is capable of improving mobility of electronic holes towards anode through donor compound. Contrary to what was expected on basis of the electronic properties of known naphthalene diimides, addition of at least one naphthalene diimide compound (I) to photoactive organic polymers useful for construction of photovoltaic devices, is capable of improving mobility of electronic holes towards anode through donor compound, and consequently allows better conversion efficiencies of solar radiation. The photoactive composition thus obtained can be advantageously used in construction of organic thin film transistors (OTFT) and organic field effect transistors (OFET).    DETAILED DESCRIPTION - A photoactive composition (C1) with a high mobility of the electronic holes, comprises: at least one organic photoactive polymer; and at least one naphthalene diimide compound of formula (I).    R 1and R 2=linear or branched 1-36C alkyl (optionally containing heteroatoms selected from O, N, and S);    R' 1and R' 2=H, or linear or branched 1-10C alkyl;    R 11to R 20=H, or linear or branched 1-16C alkyl;    a to h=0 or 1.    Provided that: at least one of a to h is not zero.    INDEPENDENT CLAIMS are included for:    (1) new naphthalene diimide compound (I') comprising (I) with the provision that a and h are 1 and at least one of b, c, d, e, f and g is 1; and    (2) process (P1) for the preparation of a photovoltaic device, involving: process (A): depositing on the anode a solution of the photoactive composition (C1) having high mobility of the electronic holes to obtain a photoactive film; and depositing a cathode on the photoactive film, where before or after the deposition of the cathode, the film is subjected to a thermal treatment at 50-200 degrees C for 5-90 minutes, or process (B): depositing on the cathode a solution of the photoactive composition (C1) having high mobility of the electronic holes to obtain a photoactive film; and depositing an anode on the photoactive film, where before or after the deposition of the anode, the film is subjected to a thermal treatment at 50-200 degrees C for 5-90 minutes.