NOVELTY - A polymer comprising 1 or more fused ring-containing unit (I), is new.    USE - New polymer is used for charge injection layer, charge transport layer, interlayer, planarizing layer, antistatic film and polymer electrolyte membrane for charge transport material, semiconducting material, electroconducting material, photoconducting material, light-emitting material, optical material, electrooptical material, electronic material, electroluminescent material for device e.g. photoluminescent device, organic field-effect transistor, thin-film transistor, organic light-emitting diode, organic light-emitting transistor, organic photovoltaic device, organic photodetector, organic solar cell, laser diode, Schottky diode, photoconductor, integrated circuit, radio frequency identification tags, security markings, security devices, flat panel display or backlights, electrophotographic device, electrophotographic recording device, organic memory device, sensor device, biosensor and biochip (all claimed).    ADVANTAGE - The polymer has excellent workability, and high solubility with respect to organic solvent. The transistor containing the polymer has high charge carrier mobility.    DETAILED DESCRIPTION - A polymer comprising 1 or more fused ring-containing unit of formula (I), is new.R=linear or branched 16-24C alkyl (optionally fluorinated).    INDEPENDENT CLAIMS are included for the following:    (1) mixture or polymer blend, which consists of polymers and compounds having semiconducting, charge transport, hole/electron transport, hole/electron blocking, electrically conducting, photoconducting or light-emitting properties;    (2) formulation, which consists of 1 or more polymers, mixture or polymer blends, and 1 or more solvents, preferably organic solvents;    (3) use of polymer, mixture, polymer blend or formulation as charge transport, semiconducting, electroconducting, photoconducting or light-emitting material in an optical, electrooptical, electronic, electroluminescent or photoluminescent device, component of device, or assembly comprising such a device or component;    (4) monomer of formula: R7-(Ar1)a-U'-(Ar2)c-R8 (VIa) R7-U'-(Ar1)a-U'-R8 (Vlb), or R7-U'-(Da)a1(Db)b1-(Dc)c1-(Dd)d1-(De)e1-(Df)f1-R8 (VIc); and    (5) preparation of polymer containing structural unit (I).    a1-f1=0 or 1;    R7-R8=Cl, Br, I, O-tosylate, O-triflate, O-mesylate, O-nonaflate, -SiMe2F, -SiMeF2, -O-SO2Z1, -B(OZ2)2 , -CZ3=C(Z3)2, -CC-H, - CC-Si(Z1)3, -ZnX0 and -Sn(Z4)3;and    X0=halo.