TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): Preparation of (Q) comprises copolymerizing a trimethyl(2-thienyl)stannane compound of formula (IA) or a 2-bromothiophene compound of formula (IB) with a 3,6-bis(5-bromo-2-thienyl)-2,5-dihydropyrrolo(3,4-c)pyrrole-1,4-dione compound of formula (IC) or a 3,6-bis-(5-(3,3,4,4-tetramethyl-1- lambda -3-(1,2,5)bromadioxolan-1-yl)-thiophen-2-yl)-2,5-dihydro-pyrrolo(3,4-c)pyrrole-1,4-dione compound of formula (ID). Preferred Components: (Q) consists essentially of the first repeating unit. Preferred Definitions:    A = thiazolo(5,4-d)thiazole moiety;    X = S; and    m = 1.    SPECIFIC COMPOUNDS - 3 Compounds (Q) are disclosed i.e. poly(3,6-dithiene-2-yl-2,5-di(2-hexyldecyl)-pyrrolo(3,4-c)pyrrole-1,4-dione)-5',5''-diyl-alt-(2,5-bis(3-ethylhexylthiophen-2yl)thiazolo(5,4-d)thiazole) of formula (Qa), poly(3,6-dithiene-2-yl-2,5-di(2-hexyldecyl)-pyrrolo(394-c)pyrrole-1,4-dione)-5',5''-diyl-alt-2,5-bis(3-octyloxythiophen-2yl)-thiazolo(5,4-d)thiazole of formula (Qb) and poly(3,6-dithiene-2-yl-2,5-di(2-hexyldecyl)-pyrrolo(3,4-c)pyrrole-1,4-dione)-5',5''-diyl-alt-2,5-bis(3-dodecylthiophen-2yl)-benzo(1,2-d;4,5-d')bisthiazole of formula (Qc).    EXAMPLE - 398 mg of 2,5-Bis(2-hexyldecyl)-3,6-bis-(5-bromo-thiophen-2-yl)-dihydropyrrolo(3,4-c)pyrrole-1,4-dione, 376 mg of 2,5-bis-(3-(2-ethyl-hexyl)-5-trimethylstannanyl-thiophen-2yl)-thiazolo(5,4-d)thiazole, 8 mg of tris(dibenzylideneacetone)dipalladium(0) and 11 mg of tri-o-tolylphosphine in 38 ml of anhydrous chlorobenzene were heated at reflux for 3 days. Then the heating was reduced to 50 degrees C. The reaction mixture was poured into 200 ml of methanol containing 5 ml of hydrochloric acid and stirred for 5 hours. The black precipitate was collected via filtration and further purified by Soxhlet extraction with methanol and hexane. Then the residue was extracted with chloroform, evaporated and dried to give 400 mg of a dark brown solid of (Qa) with a metallic appearance. Gel permeation chromatography studies of polymer (Qa) showed a number average molecular weight of 18 kg/mole with a polydispersity of 3.3.