NOVELTY - Polymer (Q) comprising a conjugated backbone with planar aryl repeating units (I) is new.    USE - (Q) or the combination is useful in optoelectronic devices, preferably in batteries or photovoltaic devices (claimed). (Q) is useful: as organic semiconductor-based devices such as organic light emitting transistors, thin-film organic solar batteries, LED and organic field-effect devices; and to prepare either p-type (donor or hole-transporting), n-type (acceptor or electron-transporting), or ambipolar semiconductor materials.    ADVANTAGE - (Q) provides solar batteries with high charge carrier mobility performance, photoelectric conversion efficiency of greater than or equal to 3%, low band-gap, high fill factor and high open circuit voltage, and exhibits properties such as optimized optical absorption, good charge transport characteristics, chemical and air stability in ambient conditions, low-temperature processability, large solubility in common solvents, and processing versatility (e.g. via various solution processes).    DETAILED DESCRIPTION - Polymer of formula (EG1-((Ar1)k-X-A-X-(Ar2)m)n-EG2) (Q) comprising a conjugated backbone with planar aryl repeating units of formula (-X-A-X-) (I) is new.    A = at least one planar aryl system comprising benzo(h)benzo(5,6)acridino(2,1,9,8-klmna)acridine, dibenzo(b,def)chrysene, pyranthrene or pyrene group of formula (a)-(m);    R = (hetero)aryl (optionally substituted with a solubilizing group comprising 1-20C-alkyl or 1-20C-alkoxy);    R1 = 1-20C-alkoxy or 1-20C-alkylthio;    X = a divalent acetylene fragment of formula (-CC-) or a thiophene unit of formula (X2);    R3, R4 = H, alkyl, alkoxy or alkylthio;    Ar1, Ar2 = a divalent arylene group, a divalent heterocyclic group or a divalent aromatic amine residue;    k, m = 0-3, preferably 1-3;    n = 2-2000, preferably 2-200; and    EG1, EG2 = end groups of (Q), preferably H, halo, trialkylstannyl unit (-Sn(alkyl)3), boronic acid unit, boronic ester unit (-B(O-alkyl)2) or (hetero)aryl unit.    INDEPENDENT CLAIMS are included for:    (1) a combination comprising (Q) with at least one fullerene compound, such as at least one 60C-fullerene compound or at least one 70C-fullerene compound or their derivatives, preferably (60)phenyl-C61-butyric acid methyl ester; and    (2) the preparation of (Q).