NOVELTY - Organic semiconductor material comprises a polymer (A) containing substituted aromatic repeating structural units.    USE - The organic semiconductor material is useful as charge transport material or thin-film transistor in semiconductor components for organic LED, photovoltaic components e.g. solar cells, photodiode, in sensors, batteries, or as organic field effect transistor, or optical waveguide or for electrophotography applications (all claimed).    ADVANTAGE - The organic semiconductor material has excellent film-forming properties, high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability, due to the polymers having excellent solubility.    DETAILED DESCRIPTION - Organic semiconductor material, comprises a polymer containing substituted aromatic repeating structural units of formula (A1-B1).    A1 = benzodithiophene repeating units of formula (I) or (II);    B1 = heterocyclic moieties of formula (III)-(X), benzo(1,2,5)thiadiazol-4,7-diyl, (1,2,5)thiadiazolo(3,4-c)pyridin-4,7-diyl, 2,3-dihydro-thieno(3,4-b)(1,4)dioxin-5,7-diyl, benzo(1,2,5)thiadiazol-4,7-diyl, phenylene moieties of formula (XI), or biphenylene moieties of formula (XII)-(XIII);    G1-G5 = 1-25C alkyl, O and/or S-interrupted 2-25C alkyl, 1-25C alkoxy, 3-12C cycloalkyl, 2-25C alkenyl, 2-25C alkynyl, 4-25C aryl or 5-25C alkylaryl (all optionally substituted by at least one halo, OH, N, -CN, or 6-18C aryl, and any 2C alkyl is optionally interrupted by -O-, -COO-, -OCO- or -S-), H or halo (F);    R1, R2 = H, 1-100C alkyl (optionally substituted by at least one halo, OH, N, -CN or 6-18C aryl, and/or interrupted by -O-, -COO-, -OCO- or -S-), -COOR103, 7-100C arylalkyl, carbamoyl, 5-12C cycloalkyl (substituted 1-3 times with 1-8C alkyl and/or 1-8C alkoxy, 6-24C aryl, preferably phenyl or 1 or 2 naphthyl (substituted 1-3 times with 1-8C alkyl, 1-8C thioalkoxy, and/or 1-8C alkoxy, or pentafluorophenyl));    p = 0-3;    R3, R3a, R4, R4a, R99, R104, R104a, R105, R105a = H, halo, 1-25C alkyl (optionally interrupted by at least one O or S), 7-25C arylalkyl or 1-25C alkoxy;    X1, X2 = -O-, -S-, -NR8-, -Si(R11)(R11a)-, -C(R7)(R7a)-, -C(=O)-, (1,2,5)thiadiazol-3,4-diyl, substituted pyrazine compound of formula (XIV), substituted 1,3-dihydro-imidazol-2-one compound of formula (XV) or substituted 2,3-dihydro-1H-pyrrole compound of formula (XVI);    one of X3, X4 = N;    other of X3, X4 = CR99;    X5 = -O- or -NR8-; either    R5, R5a = H, halo, 1-25C alkyl (optionally interrupted by at least one O or S), 6-24C aryl (optionally substituted 1-3 times with 1-8C alkyl and/or 1-8C alkoxy), 7-25C arylalkyl, CN, or 1-25C alkoxy; or    R5R5a = ring;    R6 = H, 1-18C alkyl (optionally interrupted by at least one O or S), 1-18C perfluoroalkyl, 6-24C aryl (optionally substituted 1-3 times with 1-8C alkyl and/or 1-8C alkoxy) or CN;    R7, R7a = H, 1-35C alkyl (optionally interrupted by at least one O or S) or 7-25C arylalkyl;    R8, R8a = H, 6-18C aryl (optionally substituted by 1-18C alkyl or 1-18C alkoxy) or 1-25C alkyl (optionally interrupted by at least one O or S) or 7-25C arylalkyl;    R11, R11a = 1-35C alkyl, 7-25C arylalkyl or phenyl (optionally substituted 1-3 times with 1-8C alkyl and/or 1-8C alkoxy);    R103 = 1-50C alkyl; and    R107 = H, 6-18C aryl (substituted by 1-18C alkyl or 1-18C alkoxy), 1-18C alkyl or 2-18C alkyl (interrupted by -O-).    INDEPENDENT CLAIMS are also included for:    (1) semiconductor device comprising the copolymer (A);    (2) the copolymer (A);    (3) a composition comprising at least one copolymer (A) dissolved or dispersed in a liquid medium;    (4) preparation of the composite or device comprising dissolving the polymer (A) in a liquid medium to form a solution, depositing the solution on a substrate (by spin coating, drop casting, dip coating or printing), and removing the solvent to form a thin film semiconductor on the substrate; and    (5) the preparation of the polymer (A) comprising reacting a dihalogenide of formula (X10-A-X10) (a1) with an essentially equimolar amount of a diboronic acid or diboronate of formula (X11-(B1)-X11), or reacting a dihalogenide of formula (X10-(B1)-X10) (b1) with an essentially equimolar amount of a diboronic acid or diboronate of formula (X11-A-X11) in a solvent and in the presence of a catalyst, or reacting a dihalogenide (a1) with an equimolar amount of an organotin compound of formula (X11a-(B1)-X11a), or reacting a dihalogenide (b1) with an equimolar amount of an organotin compound of formula (X11a-A-X11a).    X10 = halo;    X11 = -B(OH)2, -B(OY1a)2, substituted benzo(1,3,2)dioxaborole-2-yl moiety of formula (Ia) or substituted heterocyclic moiety of formula (Ib);    Y1a = 1-10C alkyl;    Y2a = 2-10C alkylene;    Y13a, Y14a = H, 1-10C alkyl;    X11a = -SnR207R208R209; and either    R207, R208, R209 = H or 1-6C alkyl; or    two of R207, R208, R209 = optionally branched ring.