NOVELTY - Polymer comprising substituted cyclic compounds (I) is new.    USE - The polymer is useful: in electronic, optical, or optoelectronic device comprising FET, photovoltaic device, organic light emitting device, organic LED and organic light emitting transistor (all claimed); and to prepare p-type or n-type semiconductor materials, which in turn can be used to fabricate various organic electronic articles, structures and devices, including e.g. unipolar circuitries, complementary circuitries, photodetectors, diodes, capacitors, rectifiers, and ring oscillators.    ADVANTAGE - The polymer: exhibits high carrier mobility and/or efficient light absorption or emission characteristics, thermal stability over a wide range of annealing temperatures, excellent charge transport characteristics in ambient conditions, chemical stability, low-temperature processability, satisfactory solubility in common solvents, and processing versatility (e.g. printability), solution-processability and/or good stability at ambient conditions; provides field effect devices that are thin film transistors exhibiting high performance in ambient conditions, low threshold voltages, and high current on-off ratios; and provides organic thin film transistors having long-term operability and continued high-performance in ambient conditions, and photovoltaic devices that maintain satisfactory power conversion efficiencies over an extended period of time.    DETAILED DESCRIPTION - Polymer comprising substituted cyclic compounds of formula (I) is new.    M1 = substituted fused heterocyclic moieties of formula (m1);    Ar1 = optionally substituted monocyclic aryl or heteroaryl;    X1a, X1b = S or NR1;    R1 = H or solubilizing group;    W1a, W1b = CH or C(O);    W1c, W1d = covalent bond, CH, C(O) or carbon atom bonded to Ar1;    W1e, W1f = CH or carbon atom bonded to Ar1;    M2 = substituted aryl moieties of formula (m2a), -(Ar2)m-Z1-(Ar2)m-, -(Ar2)m-, -Z1-(Ar2)m-Z1-, substituted conjugate moiety of formula (m2b) or substituted conjugate-aryl moieties of formula (m2c-m2f);    c = optionally substituted fused ring;    Ar2 = optionally substituted 5-6-membered aryl or heteroaryl;    Z1 = conjugated linear linker;    m = 0-6; and    n = greater than 2.    Provided that at least one of W1a and W1c and at least one of W1b and W1d are C(O), and only one of W1c and W1e and only one of W1d and W1f are carbon atom bonded to Ar1; and when W1c and W1d are covalent bond, X1a and X1b are NR1, and W1e and W1f are carbon atom bonded to Ar1, then R1 is divalent bridging group bonded to one of the carbon ring atoms in the ring of Ar1 forming an optionally substituted 5-6-membered ring. An INDEPENDENT CLAIM is also included for an electronic, optical, or optoelectronic device comprising a thin film semiconductor layer comprising the polymer.