TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst is one of tris(dibenzylideneacetone)palladium, bis(triphenylphosphine)palladium or tetrakis(triphenylphosphine)palladium. The amount of alkali in alkali solution is 5-20 times the amount of compound (II), and the alkali solution is sodium carbonate aqueous solution.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The first organic solvent is one of toluene and N,N-dimethylformamide.    TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): Preparation of polymer involves providing 2,2'-(9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) of formula (II) and substituted 4,6-dibromo-thieno(3,4-b)thiophene compound of formula (III) in anaerobic condition, dissolving compound (II), compound (III) and catalyst in a mol ratio of 1:1:0.005-0.05 in first organic solvent, adding alkali solution, reacting at 60 degrees C to 100 degrees C under reflux condition for 21 to 72 hours, separating and purifying alkylene group containing fluorene and thieno(3,4-b)thiophenes polymer i.e. polymer P. The separation purification step involves: reacting the reaction system in toluene and adding deionized water, taking organic phase, subjecting to decompression distilling until the organic phase is 5 ml to 15 ml, adding in anhydrous methanol, stirring, separating out precipitate, filtering, drying to form solid powder, dissolving solid powder in chloroform, passing to neutral aluminum oxide chromatographic column, removing the catalyst, collecting the chromatography liquid and distilling concentrate, then dripping methanol solvent and stirring, drying to form crude product, and extracting the crude product using Soxhlet extraction to form the polymer. The compound (II) is prepared by: supplying 2,7-dibromo-9H-fluorene compound of formula (IV) in anhydrous reaction system under the protection of nitrogen, adding the compound (IV) in reactor, then adding second organic solvent, reacting at -70 degrees C to -85 degrees C, slowly adding n-butyl lithium, stirring, reacting at -70 degrees C to -85 degrees C, to the reaction system slowly adding 2-isopropoxy-4,4,5,5-tetramethyl-1-oxo-3,2-dimethyl borane, raising the temperature to room temperature, reacting for 10-48 hours, and separating and purifying (II). The compound (IV) is prepared as follows: supplying a compound of formula 9-(bis-methylsulfanyl-methylene)-2,7-dibromo-9H-fluorene (V); heating at -5 degrees C to -10 degrees C under protection of nitrogen, dissolving compound (V) in third organic solvent and continuously stirring, then adding alkyl bromide of formula R1MgBr in diethyl ether solution, holding at -20 degrees C to 0 degrees C for 35 to 40 minutes, then adding tetrahydrofuran solution of lithium di-tetrachlorocopper, reacting for 4 to 8 hours, and then neutralizing for 10-20 minutes with sodium hydroxide solution, separating and purifying to form (IV). The compound (V) is prepared as follows: under the protection of nitrogen and room temperature condition, dissolving 2,7-dibromofluorenyl compound in anhydrous dimethyl sulfoxide, then adding potassium tert-butoxide, uniformly stirring, then adding carbon disulfide, stirring, reacting for 10-20 minutes, then dripping iodine continuously, stirring for 4 hours, and separating and purifying compound (V).