NOVELTY - Polymer comprising at least one substituted benzodione repeating unit (I) is new.    USE - The polymer and/or (IV) is useful: in an organic semiconductor material, layer or component, which is used in a semiconductor device (organic photovoltaic device, photodiode or an organic field effect transistor) (all claimed); in integrated circuits comprising many organic thin film transistor and in electronic articles comprising radio frequency identification tags, backplanes for flexible displays (e.g. personal computers, cell phones or handheld devices), smart cards, memory devices, sensors (e.g light-, image-, bio-, chemo-, mechanical- or temperature sensors), especially photodiodes, or security devices.    ADVANTAGE - The polymer has excellent solubility in organic solvents, excellent film-forming properties, high efficiency of energy conversion, excellent field-effect mobility, good on/off current rations and/or excellent stability.    DETAILED DESCRIPTION - Polymer comprising at least one substituted benzodione repeating unit of formula (-(Ar4)d-(Ar3)c-(Ar2)b-(Ar1)a-Y1-(Ar1a)a1-(Ar2a)b1-(Ar3a)c1-(Ar4a)d1-) (I) is new.    Y1 = substituted fused tricyclic moiety of formula (II) or (III);    a, a1 = 1-3;    b, c, d, b1, c1, d1 = 0-3, preferably b, c, d, b1, c1, d1 is 0 or b, b1 is 1-3;    U1 = e.g. O and S;    U2 = e.g. O and S;    T1, T2 = e.g. H, halo, OH, CN, 1-25C alkyl (optionally substituted), 5-12C cycloalkyl (optionally substituted), 7-25C arylalkyl, 6-24C aryl or 2-20C heteroaryl (both optionally substituted);    Ar2, Ar3, Ar4, Ar2a, Ar3a, Ar4a = e.g. 2,3-dihydro-thien-5,7-diyl(3,4-b)(1,4)dioxine, 2,3-dihydro-thien-5,7-diyl(3,4-b)(1,4)dithiine and -CC-; and    Ar1, Ar1a = e.g. 4,7-diyl-benzo(1,2,5)thiadiazole.    Full definitions are given in the DEFINITIONS (Full Definitions) Field. INDEPENDENT CLAIMS are also included for:    (1) substituted poly(aryl) compounds (R10-(Ar4)d-(Ar3)c-(Ar2)b-(Ar1)a-Y1-(Ar1a)a1-(Ar2a)b1-(Ar3a)c1-(Ar4a)d1-R10a) (IV);    (2) preparing organic semiconductor device, comprising applying a solution and/or dispersion of the polymer and/or (IV) in an organic solvent to a suitable substrate and removing the solvent or the process comprising evaporation of (IV);    (3) substituted poly(aryl) compounds of formula (X-(Ar4)d-(Ar3)c-(Ar2)b-(Ar1)a-Y1-(Ar1a)a1-(Ar2a)b1-(Ar3a)c1-(Ar4a)d1-X) (V); and    (4) preparation of the polymer.    R10, R10a = H, halo, CN, 1-25C alkyl, 1-25C alkoxy, 6-24C aryl or 2-20C heteroaryl (both optionally substituted by G), preferably substituted phenyl moiety of formula (IVa), substituted thiophenyl moiety of formula (IVb), substituted fused ring moiety of formula (IVc)-(IVj);    R22-R26, R29-R58 = 6-24C aryl, 2-20C heteroaryl or 4-18C cycloalkyl (all optionally substituted by G), H, halo, CN, 1-25C alkyl (optionally substituted by E and/or interrupted by D), 2-18C alkenyl, 2-18C alkynyl, 1-18C alkoxy (optionally substituted by E and/or interrupted by D) or 7-25C aralkyl (optionally substituted by G); either    R27, R28 = H, 1-25C alkyl, halo, CN or 7-25C aralkyl; or    R27R28 = alkylene or alkenylene (which may be both bonded via O and/or S to the thienyl residue and which may both have up to 25 C);    X = halo (preferably Br), ZnX12 or SNR207R208R209; either    R207-R209 = H or 1-6C alkyl; or    two of R207-R209 = ring;    X12 = halo (preferably I or Br), OS(O)2CF3, OS(O)20-aryl (preferably 4-methylbenzene-sulfonyl), OS(O)2CH3, -B(OH)2, -B(OY1a)2, substituted phenyl boronic acid moiety of formula (Va), boronic acid moiety of formula (Vb), BF4Na or BF4K;    Y1a= 1-10C alkyl;    Y2 = 2-10C alkylene comprising CY3Y4-CY5Y6 or CY7Y8-CY9Y10-CY11Y12;    Y3-Y12 = H or 1-10C alkyl, preferably C(CH3)2C(CH3)2, -C(CH3)2CH2C(CH3)2 or -CH2C(CH3)2CH2; and    Y13, Y14 = H or 1-10C alkyl.    Provided that Ar1, Ar1a are not (XVa), if b, b1, c, c1, d, d1 are 0 and R10 and R10a are H, halo, 1-25C alkyl or 1-25C alkoxy.