TECHNOLOGY FOCUS - POLYMERS - Preparation: No preparation method is given. Preferred Components: The polymeric semiconductor component is photoactive and (Q) is present in a blend material, where (Q) functions as an electron-donor compound and the blend material further comprises an electron-acceptor compound. The electron-acceptor compound is a fullerene compound or an electron-transporting polymer, which comprises a bis(imide)arene unit, where the arene group in the bis(imide)arene unit is naphthalene. Preferred Definitions:    Ar1 = optionally substituted 5-membered or 6-membered (hetero)aryl comprising phenyl, thienyl, thiazolyl, isothiazolyl, thiadiazolyl, furyl, oxazolyl, isoxazolyl, oxadiazolyl, pyrrolyl, triazolyl, tetrazolyl, pyrazolyl, imidazolyl, pyridyl, pyrimidyl, pyridazinyl or pyrazinyl (all optionally substituted with 1-5 groups of halo, CN or La1Ra1);    La1 = O, S, Se, C(O), OC(O), C(O)O or covalent bond;    Ra1 = 1-40C-(halo)alkyl, 2-40C-alkenyl or 2-40C-alkynyl; and    R1a, R1b = -CH(CH3)(CH2-CH3), -CH(CH3)(CH2-CH2-CH3), -CH(CH3)(CH2-CH2-CH2-CH3), -CH(CH3)(CH2-CH2-CH2-CH2-CH2-CH3), -CH(CH2-CH3)(CH2-CH2-CH2-CH3), -CH2-CH(CH2-CH3)(CH2-CH2-CH2-CH3), -CH2-CH2-CH(CH3)-CH2-CH2-CH2-CH(CH3)-CH3, -CH2-CH2-CH(CH3)-CH2-CH2-CH=C(CH3)-CH3, -CH2-CH((CH2)7CH3)((CH2)9CH3), -CH2-CH((CH2)5CH3)((CH2)7CH3), -CH2-CH(((CH2)3CH3)2) or -CH2-CH(((CH2)5CH3)2).    SPECIFIC COMPOUNDS - 1 Polymer (Q) is disclosed i.e. dithieno(3,2-c;2',3'-e)azepine-4,6-dione polymer of formula (Qa).    EXAMPLE - 2,8-Bis-(5-bromo-3-dodecyl-thiophen-2-yl)-5-(2-hexyl-decyl)-1,9-dithia-5-aza-cyclopenta(e)azulene-4,6-dione (0.1 mmole), 4,8-dimethoxy-2,6-bis-trimethylstannanyl-benzo(1,2-b:4,5-b')dithiophene (0.05 mmole), 4,8-bis-(2-butyl-octyloxy)-2,6-bis-trimethylstannanyl-benzo(1,2-b:4,5-b')dithiophene (0.05 mmole), tris(dibenzylideneacetone)dipalladium(0) (0.004 mmole), tri(o-tolyl)phosphine (0.016 mmole) were combined in a flask (50 ml). The flask was purged with argon before anhydrous chlorobenzene (20 ml) was added. The reaction mixture was heated at 131 degrees C for 18 hours. After cooling down to room temperature, the obtained polymer was precipitated out from methanol and further purified to obtain dithieno(3,2-c;2',3'-e)azepine-4,6-dione polymer (Qa) (100 mg, yield 73.5%).