NOVELTY - Polymer comprising a repeating unit of substituted fused diketopyrrolopyrrole compounds (I) is new.    USE - (I) and (III) are useful in organic semiconductor material, layer or component of electronic device, where the device is organic photovoltaic device, photodiode, or organic FET (all claimed).    ADVANTAGE - (I) and (III) have excellent solubility in organic solvents and excellent film-forming properties, high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability.    DETAILED DESCRIPTION - Polymer comprising a repeating unit of substituted fused diketopyrrolopyrrole compounds of formula (I) is new.    a, x, b, y, c, z = 0-3;    R1, R2 = e.g. 1-100C alkyl (optionally substituted by 1-12C alkyl, 1-12C alkoxy, halo, 5-12C cycloalkyl, nitro, CN, vinyl, allyl, 6-24C aryl, 2-20C heteroaryl, or E1Si- and/or optionally interrupted by -O-, -S-, -NR39-, -COO-, -CO-, -OCO-, 6-24C arylene, 2-20C heteroarylene, 3-12C cycloalkylene, or D1-Si-1);    E1Si- = -SiR161R162R163 or -OSiR161R162R163;    D1Si-1 = -SiR161R162-, -SiR161R162(OSiR161R162)d- or -O-SiR161R162-;    R161-R163 = e.g. H, -O-SiR164R165R166, -(OSiR164R165)d-R166, NR167R168, halo or phenyl (substituted 1-3 times by 1-24C alkyl, halo, CN or 1-25C alkoxy);    R164-R166 = H, -OSiR169R170R171, -(O-SiR169R170)d-R171, NR167R168, halo, phenyl (optionally substituted 1-3 times by 1-24C alkyl, halo, CN or 1-25C alkoxy);    R169-R171 = e.g. H, NR167R168 or halo;    R167, R168 = 6-18C aryl (optionally substituted by 1-18C alkyl, or 1-18C alkoxy) or 1-25C alkyl (optionally interrupted by O or S), 7-25C arylalkyl or H;    d = 1-50;    R39 = 1-18C alkyl, 1-18C haloalkyl, 7-25C arylalkyl, 1-18C alkanoyl or H;    Ar1, Ar2, Ar3, Ar1a, Ar2a, Ar3a = e.g. (1,3)thiazolo(5,4-d)(1,3)thiazole-2,5-diyl, or 2,3-dihydrothieno(3,4-b)(1,4)dioxine-5,7-diyl;    R3, R3a = H, halo, E1Si-, halo-1-25C alkyl, CN, 1-25C alkyl (optionally interrupted by O or S), 7-25C arylalkyl, 1-25C alkyl (substituted with E1Si- or 1-25C alkoxy);    R4 = H, halo, E1Si-, halo-1-25C alkyl, CN, 1-25C alkyl (optionally interrupted by at least one O or S), 7-25C arylalkyl, 1-25C alkyl (substituted with E-Si-1 or 1-25C alkoxy);    R8 = 6-18C aryl (substituted by 1-18C alkyl, or 1-18C alkoxy) or 1-25C alkyl (optionally interrupted by O or S), 1-25C alkyl (substituted with E1Si-) or 7-25C arylalkyl or H; and    R114 = 1-25C alkyl (optionally interrupted by at least one O, or S.    With provisos, Full definitions are given in the DEFINITIONS Field.    INDEPENDENT CLAIMS are also included for:    (1) substituted compounds of formula (A11a-Y1q(A13a-Y15)o(A14a-Y16)p(A15a-Y17)qA12a) (III);    (2) an organic semiconductor material, layer or component, comprising the polymer and/or (III);    (3) an electronic device, comprising the polymer, (III) and/or the organic semiconductor material, layer or component;    (4) preparing the electronic device, comprising applying a solution and/or dispersion of the polymer and/or (III) in organic solvent to substrate and removing the solvent, where the process comprises evaporation of (III);    (5) substituted fused 2,5-dihydropyrrolo(3,4-c)pyrrole-1,4-dione compounds of formula (V);    (6) preparing polymer of substituted compounds of formula (II), comprising reacting dihalogenide of formula (X10AX10) with equimolar amount of a diboronic acid or diboronate of formula of formula (X11(COM1)X11) or reacting dihalogenide of formula (X10(COM1)X10), with an equimolar amount of diboronic acid or diboronate of formula (X11AX11) in a solvent and in the presence of a catalyst, or reacting a dihalogenide of formula (X10AX10) with equimolar amount of organo tin compound to formula (X11a(-COM1)-X11a) or reacting a dihalogenide of formula (X10(-COM1)-X10) with an equimolar amount of organo tin compound of formula (X11a-A-X11a); and    (7) a polymer comprising a repeating unit of substituted compounds of formula (A111a-Y1q-A3-Y15-(A4-Y16)p-(A5-Y17)q-A112a) (X).    Y1q, Y15-Y17 = substituted 2,5-dihydropyrrolo(3,4-c)pyrrole-1,4-dione moiety of formula (y1);    o, p, r = o or 1;    A11a, A12a = (Ar1)a-(Ar2)b-(Ar3)c-R10;    A13a-A15a = (Ar14)k-(Ar15)l-(Ar6)r-(Ar7)z-R10;    k,l, r, z = 0-3;    R10 = H, halo, CN, 1-25C alkyl (optionally substituted at least one time by E1Si- and/or interrupted at least one time by D, E1Si-, 1-25C alkyl (substituted by at least one time by E1Si- and/or interrupted by D1-Si-1), CH3C=C(R214)(R215), COO-1-8C-alkyl, 4-18C cycloalkyl, 4-18C cycloalkyl (substituted by G1, 2-18C alkenyl, 2-18C alkynyl, 1-18C thioalkoxy, 1-18C alkoxy, 1-18C alkoxy which is substituted by E1 and/or interrupted by D1, 7-25C aralkyl, 7-25C aralkyl, which is substituted by G1, or substituted thiophene moiety of formula (IVb); either    R27, R28 = H, 1-25C alkyl, halo, CN or 7-25C aralkyl; or    R27R28 = alkylene or alkenylene which optionally both bonded via oxygen and/or sulfur to the thienyl residue and which optionally have up to 25 carbon atoms;    R58 = H, halo, CN, 1-25C alkyl (optionally substituted by E1 and/or interrupted by D1, 6-24C aryl (optionally substituted by G1), 2-2C heteroaryl (optionally substituted by G1, 4-18C cycloalkyl (optionally substituted by G1), 2-18C alkenyl, 2-18C alkynyl, 1-18C alkoxy (optionally substituted by E1 and/or interrupted by D1), 7-25C aralkyl (optionally substituted by G1);    D1 = -CO-, -COO-, -S-, -O-, or -NR112-;    E1 = 1-8C thioalkoxy, 1-8C alkoxy, CN, -NR112R113, -CCNR112R113, or halo;    G1 = E, or 1-18C alkyl;    R112, R113 = H, 6-18C aryl (optionally substituted by 1-18C alkyl or 1-18C alkoxy), 1-18C alkyl, or 1-18C alkyl which is interrupted by -O-;    X10 = halo;    X11 = -B(OH)2, -B(OY1a)2, substituted 2-(dimethylboryloxy)phenol moiety of formula (15a) or oxygen containing heterocyclic moiety of formula (16a);    Y1a = 1-10C alkyl or 2-10C alkylene;    A111a, A112a = -(Ar1)a-(Ar2)b-(Ar3)c-;    X11a = -SnR207R208R209;    X2, X2a = halo, ZnX12 or -SnR207R208R209; either    R207-R209 = H or 1-6C alkyl; or    two of R207R208R209 = ring;    X12 = halo or -OS(O)2CF3, -OS(O)2-aryl, -OS(O)2CH3, -B(OH)2, -B(OY1)2, -BF4Na, or -BF4K;    Y1 = 1-10C alkyl;    Y2 = 2-10C alkylene such as CY3Y4CY5Y6, or CY7Y8CY9Y10 CY11Y12;    Y3-Y14 = H or 1-10C alkyl;    -COM1- = repeating unit, which has the meaning of Ar2, or -(Ar14)s-( Ar15)t-(Ar16)u-(Ar17)v-;    s, t = 1;    u, v = 0 or 1;    Ar14-Ar17 = substituted thiophene moiety of formula (t1), substituted sulfur containing heterocyclic moiety of formula (t2), substituted thieno(3,2-b)thiophene moiety of formula (t3), substituted thieno(2,3-b)thiophene moiety of formula (t4) or (1,3)thiazolo(5,4-d)(1,3)thiazole-2,5-diyl;    X5, X6 = N; and    other of X5, X6 = CR14; and    R14, R14a, R17, R17a = H, or 1-25C alkyl.