TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The polymer further contains substituted fluorenyl thiophene-containing structural unit of formula (3) and fluorenyl terthiophene-containing structural unit of formula (4).n=2 or more;o,p=0 or more;ando+p=1 or more.Preferred Material: The organic photoelectric transducer (10) contains an organic layer (2) formed using the polymer composition provided between a pair of transparent or semi-transparent electrodes (3a,3b). Preferred Definitions:    Q,R=H.    EXAMPLE - (In g) dioxaborolane-fluorene-containing compound of formula (A) (7.928), 5,5'-dibromo-3",4"-dihexyl-quinquethiophene of formula (B) (13), Aliquat336 (RTM: methyltrioctyl ammonium chloride) (4.979), toluene (405 ml), dichloro bis(triphenyl phosphine)palladium(II) (0.02) and aqueous solution of sodium carbonate (42.2 ml) were reacted at 105 degrees C in presence of argon atmosphere. Then, phenylboronic acid (2.6) and toluene (1.8 ml) was added to the reaction mixture and reacted at 105 degrees C for 16 hours. Then, toluene (700 ml) and aqueous solution of sodium-diethyldithiocarbamate trihydrate (200 ml) were added and reacted at 85 degrees C for 3 hours. Then, the reaction mixture was washed using ion-exchange water (300 ml) and acetic acid (300 ml) at 60 degrees C. Then, the reaction mixture was concentrated and was added to methanol, to obtain precipitates of penta thienyl-fluorene copolymer of formula (C) (12.21). The obtained precipitate was dried under vacuum at 50 degrees C, to obtain penta thienyl-fluorene copolymer (C) having weight average molecular weight of 5.4x 104 and number average molecular weight of 1.1x 105. The obtained copolymer (C) and 6,6-phenyl-butyric acid methyl ester was mixed in the mol ratio of 1:3 and was dissolved in ortho-dichlorobenzene, to obtain coating liquid. The obtained coating liquid was coated on a glass substrate and heated at 130 degrees C for 10 minutes, to form organic layer. Then, the organic layer was interposed between lithium fluoride and aluminum electrodes, to form organic thin film solar cell. The obtained organic thin film solar cell had excellent photoelectric conversion efficiency, favorable open end voltage and short circuit current density.    m=2 or more.