NOVELTY - Polycyclic aryl compounds (A) are new.    USE - (A) are useful in a thin film semiconductor, which is useful in: a composite comprising a substrate and the thin film semiconductor on the substrate; and an electronic device, an optical device, or an optoelectronic device, preferably a field effect transistor device (all claimed). (A) are useful in photovoltaics or solar cells.    ADVANTAGE - (A) exhibits broad optical absorption and/or tuned redox properties and bulk carrier mobilities. (A) exhibits high carrier mobility and/or good current modulation characteristics. (A) has improved solution-processability, good charge transport characteristics, good solubility in a variety of common solvents and/or good stability at ambient conditions.    DETAILED DESCRIPTION - Polycyclic aryl compounds (A) of formula (I) and (II) are new.    W1, W2 = -(CR1aR1b)m- or -(SiR1cR1d)-;    Z1, Z2 = O, S, -CC-, and a covalent bond;    L = an electron-withdrawing group;    R1a, R1b, R1c, R1d = H, 1-20C alkyl group or 1-20C haloalkyl group;    R1, R1a, R1aa, R2, R2a, R2aa = H, 1-20C alkyl group, 2-20C alkenyl group or 1-20C haloalkyl group;    m = 0-10; and    n = 0-8.    INDEPENDENT CLAIMS are included for:    (1) a thin film semiconductor comprising (A);    (2) a composite comprising a substrate (20) and the thin film semiconductor on the substrate;    (3) an electronic device, an optical device, or an optoelectronic device comprising the thin film semiconductor; and    (4) a field effect transistor device comprising a source electrode, a drain electrode, a gate electrode, and the thin film semiconductor in contact with a dielectric material, where the dielectric material comprises an organic dielectric material, an inorganic dielectric material, or a hybrid organic/inorganic dielectric material.    DESCRIPTION OF DRAWING(S) - The figure shows a representative structure of a bulkheterojunction organic photovoltaic device (such as solar cell).    Substrate (20)    Anode (22)    Photoactive layer (24)    Cathode. (26)