TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises reacting 4,6-dibromothieno(3,4-b)thiophene-2-carbaldehyde compound of formula (IA) and spiro(cyclopenta-1,3-diene-5,9'-fluorene) compound of formula (IB) in the presence of organic solvent according to mole ratio of 1:1-1:1.5 under inert gas atmosphere, and carrying out Stille coupling reaction with catalyst at 60-120 degrees C for 24-72 hours. Preferred Method: (IB) is prepared by reacting 1-bromo-2-phenyl-benzene compound of formula (Ia) and bromine sulfur compound of formula (Ib) with tetrahydrofuran to obtain bromine sulfur compound of formula (Ic) under the protection of inert gas, cooling the mixture at -78 degrees C, slowly adding (Ic) with n-butyl lithium in a mole ratio of 1:1.2-1:1.5, stirring the reaction mixture at 78 degrees C, mixing tetrahydrofuran solution, (Ia) and (Ib) according to a mole ratio of 1:1:1.3, recovering the mixture at room temperature, continuously reacting the mixture for 20-24 hours to obtain crude product of (Ic), dissolving the crude product in glacial acetic acid, adding concentrated hydrochloric acid, dehydrating agent and glacial acetic acid in a volume ratio of 50:1, stirring and refluxing the reaction mixture at 102-105 degrees C for 3-5 hours, cooling the mixture, then adding water, separating out the precipitate, reacting (Ic) with solvent and catalyst to obtain bromine sulfur compound of formula (Id), performing Stille coupling reaction at 60-120 degrees C for 24-48 hours, reacting (Id) and trimethyl(2-thienyl)stannane compound of formula (Ie) to obtain 2-(2-thienyl)-4H-cyclopenta(b)thiophene compound of formula (If) according to mole ratio of 1:2.2-1:2.5 under the protection of inert gas, reacting (If) with tetrahydrofuran under protection of inert gas to obtain (IB). Preferred Components: The mole ratio of n-butyl lithium and (If) is 1:2.2-1:2.5. The mole ratio of trimethyl tin chloride and (If) is 1:21:2.5. The catalyst is bis(triphenylphosphine)palladium dichloride, tetrakis(triphenylphosphine)palladium, (dibenzylideneacetone)dipalladium or tris(dibenzylideneacetone)dipalladium, and is present in an amount of 0.01-5 mol.%. The mole ratio of tris(dibenzylideneacetone)dipalladium, tris(dibenzylideneacetone)dipalladium and tri-o-tolylphosphine is 1:2-1:20.