TECHNOLOGY FOCUS - POLYMERS - Preparation: 3,6-Dibromo-thienothiophene and 2-trimethylstannyl-4-alkyl-5-trimethylsilyl thiophene of formula (IV), and halogen of thienothiophene is substituted by thiophene having an alkyl group, to obtain a trimethyl(trimethylsilyl)thiophenyl-thieno-thiophenyl-thiophenyl-silane derivative of formula (V). Bis(pinacolato)diboron is reacted with compound (V), to obtain a (bis(tetramethyl-dioxaborolanyl)((trimethylsilyl)thiophenyl)thieno-thiophenyl)thiophenyl)trimethylsilane derivative of formula (VI). Compound (VI) is oxidized using potassium peroxymonosulfate, potassium bisulfate, or potassium sulfate, to obtain a bis((trimethylsilyl)thiophenyl)-thieno-thiophene-dione derivative of formula (VII). Compound (VII) is halogenated using e.g. N-bromosuccinimide to obtain a bis(bromothiophenyl)-thieno-thiophene-dione derivative of formula (VIII). Compound (VIII) is reacted with substituted 5,5-bis(trimethylstannyl)-2,2-bithiophene of formula (IX) and polymerized to obtain compound (I). Preferred Compound: Compound (I) is preferably of formula (III).R3=H, when R1 is substituent other than H, and alkyl or substituent having functional group at terminal of alkyl group, when R1 is H. EXAMPLE - 3.76 g Trimethyl(3-(2-octyldodecyl)-5-(6-(4-(2-octyldodecyl)-5-(trimethylsilyl)thiophen-2-yl)-2,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thieno(3,2-b)thiophen-3-yl)thiophen-2-yl)silane, 120 mL tetrahydrofuran, 50 mL acetone, and 30 mL water were stirred in nitrogen atmosphere under light-shielding conditions. 14.6 g Oxone (RTM: potassium peroxomonosulfate) was added and stirred at room temperature for 3 hours. Extraction was carried out using chloroform, after adding sodium hydrosulfite aqueous solution. The organic layer was washed with saturated salt solution and water, and dried. The solvent was removed and the product was separated and purified using silica gel column chromatography using hexane/dichloromethane (9:1) as mobile phase, to obtain 0.64 g 3,6-bis(4-(2-octyldodecyl)-5-(trimethylsilyl)thiophen-2-yl)-2H,5H-thieno(3,2-b)thiophene-2,5-dione as red solid. 0.45 g 3,6-Bis(4-(2-octyldodecyl)-5-(trimethylsilyl)thiophen-2-yl)-2H,5H-thieno(3,2-b)thiophene-2,5-dione, 0.15 g N-bromosuccinimide, and 50 mL tetrahydrofuran were stirred in nitrogen atmosphere for 12 hours under light-shielding conditions. Extraction was carried out using chloroform, after adding water to the reaction liquid. The organic layer was washed with saturated salt solution and water, and dried. Solvent was removed, and the product was separated and purified using silica gel column chromatography using hexane/dichloromethane (9:1) as mobile phase, to obtain 0.38 g 3,6-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-2H,5H-thieno(3,2-b)thiophene-2,5-dione as red solid. 0.105 g 3,6-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-2H,5H-thieno(3,2-b)thiophene-2,5-dione, 49 mg 5,5'-bis(trimethylstannyl)-2,2'-bithiophene, 3.5 mg tetrakis(triphenylphosphine)palladium, and 5 mL toluene were sealed and microwave-reacted at 180 degrees C for 40 minutes. After cooling to room temperature, the reaction liquid was poured into hydrochloric acid/methanol (200 mL/5 mL) solution and stirred for 5 hours. Extraction was carried out using chlorobenzene, after filtering, washing with methanol, hexane, and chloroform. The concentrated solution was poured into methanol and 100 mg high-molecular compound of formula (A) was obtained as plum solid. The compound had a number average molecular weight of 42200, a weight average molecular weight of 95900, and a dispersion degree of 2.3. The obtained compound provided a bottom-gate top contact type transistor element having a Hall mobility of 0.35 cm2/V.second and an ON/OFF ratio of 105.