TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): Preparation of (I) comprises obtaining or providing at least one bis-heteroaryl substituted diketopyrrolopyrrole monomer of formula (C1), obtaining or providing at least one bis-leaving group substituted ethylene monomer of formula (LG2-C(R22)=C(R22a)(LG2)) (D1) and reacting a mixture comprising the first bis-heteroaryl substituted diketopyrrolopyrrole monomer and the bis-leaving group substituted ethylene monomer in the presence of a transition metal catalyst complex.LG1 = a leaving group such as Br;LG2 = a leaving group capable of being eliminated by reacting with LG1, such as Sn(R2b)3; andR2b = alkyl or aryl.Preferred Process: In the preparation of (I): the mixture comprises susbtantially equimolar amounts of the first bis-heteroaryl substituted diketopyrrolopyrrole monomer and the bis-leaving group substituted ethylene monomer; and the mixture is substantially free of any monomer other than the first bis-heteroaryl substituted diketopyrrolopyrrole monomer and the bis-leaving group substituted ethylene monomer. Preferred Components: (I) are homopolymers. (I) further comprise 0-50 mol.% of another repeating units (BB), which are not (II) comprising a mixture of diketopyrrolopyrrole repeating units of formula (III) and (IV). (BB) is of formula (V) or (VI). (I) have: a number average degree of polymerization of at least 10, as determined by gel permeation chromatography using polystyrene calibration standards; and a solubility in a solvent consisting of toluene, xylene, mesitylene, tetrahydrofuran, chloroform, chlorobenzene and/or dichlorobenzene of at least 10 mg/ml at 25-50 degrees C. The mixture further comprises at least one self-reacting monomer of formula (LG1-hAr1b-LG2).R11, R11a, R21, R21a = linear, branched or cyclic 1-C30-alkyl or its fluorinated derivatives;hAr11, hAr11a , hAr21, hAr21a = 1-60C-heteroaryls (AA);R12, R12a, R22, R22a = 1-30C-alkyl, 1-30C-fluoroalkyl, 1-30C-alkoxy, 1-30C-aryl, 1-30C-heteroaryl, 1-30C-carboxyalkyl, H, CN or acetoxy; andhAr1b = hAr1.Provided that at least one of R11, R11a, hAr11 and hAr11a in formula (III) differs from its homologue. Preferred Definitions:    hAr1, hAr1a = thiophene moiety, 2,3-dihydro-thieno(3,4-b)(1,4)dioxine moiety, selenophene moiety, furan moiety, thiophene 1,1-dioxide moiety, thiazole moiety, (1,3,4)thiadiazole moiety, (1,3,4)oxadiazole moiety, oxazole moiety, (2,2')bithiophenyl moiety, (2,5')bithiazolyl moiety, thieno(3,2-b)thiophene moiety, thieno(2,3-b)thiophene moiety, thiazolo(5,4-d)thiazole moiety, dithieno(3,2-b,2',3'-d)thiophene moiety, thiophene group of formula (a1), 5,6-dihydro-4H-cyclopenta(c)thiophene group of formula (b1), 1H-pyrrole group of formula (c1), 1H-pyrazole group of formula (d1), (2,2')bithiophenyl group of formula (e1), (2,2')biselenophenyl group of formula (f1), (2,2')bithiazolyl group of formula (g1), thieno(3,2-b)thiophene group of formula (h1), thieno(3,4-b)thiophene group of formula (i1), thieno(3,4-d)thiazole group of formula (j1), thieno(3,4-c)pyrrole-4,6-dione group of formula (k1), 7H-3,4-dithia-7-sila-cyclopenta(a)pentalene group of formula (l1), 4H-dithieno(3,2-b,2',3'-d)pyrrole group of formula (m1), 4H-cyclopenta(2,1-b,3,4-b')dithiophene group of formula (n1), dithieno(3,2-b,2',3'-d)thiophene group of formula (o1), benzo(1,2-b,4,5-b')dithiophene group of formula (p1), 1,5-dithia-3-aza-s-indacene group of formula (r1), benzo(c)thiophene group of formula (s1), thieno(3,4-b)pyrazine group of formula (t1), thieno(3,4-b)pyrazine group of formula (u1), 1,4,9-trithia-trindene group of formula (w1), 3,4,7-trithia-1,6-diaza-trindene group of formula (x1), 1,6,7-trithia-3-aza-trindene group of formula (y1), 3H-4,7-trithia-trindene group of formula (z1), 3H-4,7-trithia-3,6-diaza-trindene group of formula (aa1), 4H-(1)benzosilolo(3,2-b)thiophene group of formula (aa2) or 4H-thieno(3,2-b)indole group of formula (aa3);    R3a = R3; and    R4a = R4.    EXAMPLE - 3,6-Bis(5-bromo-thiophen-2-yl)-2,5-bis(2-hexyldecyl)pyrrolo(3,4-c)pyrrole-1,4-dione (480 mg) and trans-1,2-bis(tributylstannyl)ethylene (320.8 mg) was dissolved in anhydrous chlorobenzene (18 ml) and purged with argon. Further tris(dibenzylideneacetone)dipalladium(0) (9.7 mg) and tris(o-tolyl)phosphine (12.9 mg) were added and degassed. After purging with argon for 5 minutes, the solution was refluxed at 120 degrees C for 2 days. The solution was then quenched and precipitated into methanol. The solid was filtered, extracted with acetone and dried in vacuum oven to afford poly(3,6-(2,5-bis(2-hexyldecyl)pyrrolo(3,4-c)pyrrole-1,4-dione)-alt-1,2-bis-(2'-thienyl)vinyl-5',5''-diyl) (398 mg).