TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): Compound of formula (A), (B) and (C) are subjected to Suzuki coupling reaction under alkaline environment in presence of catalyst and organic solvent to obtain compound of formula (E). The compound (E) and N-bromosuccinimide are subjected to bromination reaction in presence of organic solvent to obtain dibromo compounds of formula (E). The dibromo compounds and malononitrile are subjected to condensation reaction in presence of catalyst, condensing agent and organic solvent to obtain quinoid silafluorene organic semiconductor material (I), or compound of formula (D) and malononitrile are subjected to condensation reaction in presence of catalyst, condensing agent and organic solvent to obtain quinoid silafluorene organic semiconductor material (I).m,n=1-10 or 0.Preferred Process: The preparation of compound (A) involves reacting 4,4'-dibromo-2,2'-diisobutyl phthalate, alkyl derivative of lithium and dialkyl dichlorosilane in presence of organic solvent to obtain 2,7-dibromo-9,9-dialkyl silafluorene compounds, and subjecting 2,7-dibromo-9,9-dialkyl silafluorene compounds, alkyl derivative of lithium and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-oxypentaborane to condensation reaction in presence of organic solvent. Preferred Composition: The molar ratio of 4,4'-dibromo-2,2'-diisobutyl phthalate, alkyl derivative of lithium and dialkyl dichlorosilane is 1:2-4:2-4. The molar ratio of three reactants 2,7-dibromo-9,9-dialkyl silafluorene compounds, alkyl derivative of lithium and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2- oxypentaborane is 1:2-4:2-4. The organic solvent used in the condensation reaction is tetrahydrofuran, ether, methylene chloride, chloroform or ethyl acetate. The molar ratio of compounds (A), (B) and (C) in Suzuki coupling reaction is 1:1-1.5:1-1.5. The alkali in the alkaline environment is sodium hydroxide, sodium carbonate, sodium bicarbonate or tetraethyl ammonium hydroxide. The catalyst is tetrakis(triphenylphosphine)palladium, tris(dibenzylideneacetone)dipalladium/tri(o-tolyl)phosphine or bis(triphenylphosphine)palladium chloride. The Moore content of compound (A) is 0.05-20%. The organic solvent is ethylene glycol dimethyl ether, tetrahydrofuran, ether, methylene chloride, chloroform or ethyl acetate. The molar ratio of compound (E) and N-bromosuccinimide is 1:2-2.5. The organic solvent used in bromination reaction is N,N-dimethylformamide, tetrahydrofuran, ether, methylene chloride, chloroform, ethyl acetate or acetic acid. The molar ratio of dibromo compounds and malononitrile is 1:2-10. The organic solvent used in condensation reaction of dibromo compounds and malononitrile is ethylene glycol dimethyl ether, tetrahydrofuran, ether, methylene chloride, chloroform or ethyl acetate. The catalyst used in condensation reaction of dibromo compounds and malononitrile is organic palladium (0.05-20 mol% of dibromo compounds). The condensing agent is sodium hydride or sodium alkoxide. Preferred Definitions:    R1,R2,R5,R6=H,-C6H13 or -C20H41 alkyl;and    R3,R4=-CH3, -C6H13 or -C20H41 alkyl.