NOVELTY - Polymer (Q1) comprising 2,5-dihydro-pyrrolo(3,4-c)pyrrole-1,4-dione repeating units is new.    USE - (Q1) and/or the organic semiconductor material, layer or component is useful in an electronic device comprising organic LED, an organic photovoltaic device, a photodiode, a sensor, photoconductor or an organic FET (all claimed). (Q1) is useful in solution-processed electronic devices such as organic photovoltaics (solar cells), photodiodes and organic field effect transistors.    ADVANTAGE - (Q1): shows high absorption in the wavelength range above 1000 nm and high lying lowest unoccupied molecular orbital associated with a very low band gap, which allows them to provide high short-circuit current when used as photoactive material in combination with commercial C60/C70 fullerene derivatives in solar cells or photodiodes; and shows excellent solubility in organic solvents and excellent film-forming properties and stability.    DETAILED DESCRIPTION - Polymer (Q1) comprising 2,5-dihydro-pyrrolo(3,4-c)pyrrole-1,4-dione repeating units of formula (I), (IIa), (IIb) or (III), is new.    A = a divalent radical of formula (IV);    Ar1, Ar1a, Ar2, Ar2a = divalent radical of formula (a1) or (a2);    X1-X3 = O, S (preferred) or Se;    R3 = H, 1-25C-alkyl, 3-12C-cycloalkyl, 1-25C-alkoxy, 1-25C-thioalkyl, 2-25C-alkenyl or 2-25C-alkynyl;    R201, R201a = 1-100C-alkyl, 2-100C-alkenyl or 2-100C-alkynyl, -C(O)OR103 (optionally substituted by one or more halo, hydroxyl, nitro, -CN or 6-18C-aryl groups and/or interrupted by -O-, -C(O)O-, -OC(O)- or -S-), or 7-25C-arylalkyl, carbamoyl, 5-12C-cycloalkyl (all optionally substituted 1-3 with 1-100C-alkyl and/or 1-100C-alkoxy), or 6-24C-aryl, preferably phenyl or 1- or 2-naphthyl (optionally substituted 1-3 times with 1-100C-alkyl, 1-100C-thioalkoxy and/or 1-100C-alkoxy), pentafluorophenyl or H;    R103 = 1-25C-alkyl (optionally interrupted with one or more O or S);    D1 = -(Ar4)k-(Ar5)l-(Ar6)v-(Ar7)z- (V);    x, r+s = 0.01-0.99;    y, t+u = 0.99-0.01, where x+y is 1 and r+s+t+u is 1;    k, v, z = 0 or 1;    l = 1;    Ar4-Ar7 = divalent radical of formula (b1)-(b8), where at least one of Ar4-Ar7 is (b8);    X5, X6 = N or CR14, where one of X5 and X6 is N and the other is CR14;    R14, R14a, R17, R17a = 1-25C-alkyl (optionally interrupted by one or more O) or H;    R116 = 6-18C-aryl (optionally substituted by 1-18C-alkyl or 1-18C-alkoxy), 1-25C-alkyl (optionally interrupted by one or more O or S) or 7-25C-arylalkyl; either    R1, R2 = 1-25C-alkoxy or 1-25C-thioalkyl; or    R1+R2 = -Y2-C(R206)(R206a)-Y1- or -Y2-C(R206)(R206a)-C(R207a)(R207)-Y1-;    Y1, Y2 = O or S;    R206, R206a, R207, R207a = 1-18C-alkyl, 1-18C-alkoxy (both optionally interrupted one or more times by O), 1-18C-fluoroalkyl, 2-18C-alkenyl, 2-18C-alkynyl, CN or H;    B1 = a group (IV), which is different from (A), or (V) which is different from (D1); and    E = a group (V), which is different from (D1), or a group (IV), which is different from A.    INDEPENDENT CLAIMS are included for:    (1) an organic semiconductor material, layer or component, comprising (Q1);    (2) an electronic device, comprising (Q1) and/or the organic semiconductor material, layer or component; and    (3) preparing an electronic device, comprising applying a solution and/or dispersion of (Q1) in an organic solvent to a substrate and removing the solvent.