TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): Thieno(3,2-b)thiophene-5-formaldehyde compound of formula (Ia1) is reacted with 2,5-dibromo-thiophene diethylphosphate compound of formula (Ia2) in the presence of N,N'-dimethylformamide and sodium methylate, to obtain a precursor of formula (Ia). The precursor, 2,5-dibromo-thiophene precursor of formula (IIa), and 2,5-tributylthiophene compound of formula (1b) are reacted in the presence of toluene with reflux for 12-24 hours, to obtain the new polymer. Preferred Polymer: The polymer is preferably of formula (P1), (P2) or (P3).a=5-200;b:c=0.75-0.25;andd:e=0.25:0.75. Preferred Definitions:    M=S or Se;    R1=vinylidene or hexylidene trivinyl;    m=1;and    R2-R11=methyl, ethyl, isopropyl, t-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, vinyl, allyl, 2-butenyl, 3-pentenyl, propargyl, 3-propynyl, phenyl, o-methylphenyl, naphthyl, anthryl, amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, dimethylphenylamino, methoxy, ethoxy, butoxy, ethylhexyloxy, phenoxy, 1-naphthalenyloxy, 2-naphthalenyloxy, pyridyloxy, pyrazolyloxy, pyrimidinyloxy, quinolyl, acetyl, benzoyl, formyl, pivalyl, methoxycarbonyl, ethoxycarbonyl, phenoxycarbonyl, acetoxy, benzoyloxy, aminoacetyl, aminobenzoyl, methoxycarbonylamino, phenoxycarbonylamino, mesylamino, benzenesulfonylamino, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl, carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, methylthio, ethylthio, phenylthio, pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzothiazolylthio, mesyl, toluenesulfonyl, methanesulfinyl, phenylsulfinyl, ureido, methylureido, phenylureido, phosphoric acid amido, hydroxy, thio, fluoro, chloro, bromo, iodo, cyano, sulfonic acid group, carboxy, nitro, hydroxamate, sulfinyl, hydrazine, imino, imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidinyl, morpholinyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, trimethylsilylmethyl, or triphenylsilylmethyl.