NOVELTY - Preparing composition comprising at least one polythiophene containing repeating units of substituted dihydro-thieno(3,4-b)(1,4)dioxine (I) and/or substituted dihydro-2H-thieno(3,4-b)(1,4)dioxepine (II), and at least one further polymer, comprises: mixing polythiophene with the further polymer and optionally adding solvent; or dissolving the polythiophene in a diluent and dissolving further polymer in diluent and mixing the two solutions; or producing the polythiophene by polymerizing the corresponding monomeric compounds with at least one oxidizing agent in a solvent.    USE - The process is useful for preparing the composition (claimed), which is useful for producing: hole-injecting or hole-transporting layers in electroluminescing (EL) arrangements, organic solar cells, organic laser diodes, organic thin film transistors or organic field effect transistors; and electrodes or electrically conducting coatings.    ADVANTAGE - The process provides the composition, which produces the EL arrangements (i.e. LEDs) having high durability, high luminosity, low applied voltages and high rectification ratio than the conventional EL arrangements.    DETAILED DESCRIPTION - Preparing a composition comprising at least one polythiophene containing repeating units of substituted dihydro-thieno(3,4-b)(1,4)dioxine of formula (I) and/or substituted dihydro-2H-thieno(3,4-b)(1,4)dioxepine of formula (II), and at least one further polymer (that is different than the polythiophene and represents a partially fluorinated or perfluorinated polymer comprising substituted sulfonate moiety of formula (SO3-M2+) (A1) or a partially fluorinated or perfluorinated polymer comprising substituted carboxylate moiety of formula (COO-M2+) (A2), or their salts, comprises: mixing polythiophene with the further polymer and optionally adding solvent to this mixture; or dissolving the polythiophene in at least one diluent and dissolving the further polymer in the diluent and mixing these two solutions; or producing the polythiophene by polymerizing the corresponding monomeric compounds with at least one oxidizing agent in a solvent, where an exchange of solvent or addition of further solvents may take place after completion of polymerization, and mixing the polythiophene solution with further polymer, where the further polymer is optionally dissolved in the diluent.    R1 = -(CH2)x-O-(CH2)y-R3;    R3 = SO3-M1+ or COO-M1+;    M1+ = H+, Li+, Na+, K+, Rb+, Cs+, or NH4+;    R2 = 1-20C alkyl, 6-14C aryl, R1, or -(CH2)q-O-(CH2CH2)r-R4, or H;    R4 = 1-4C alkyl;    x, q = 0-10;    r = 1-12;    y = 1-18; and    M2+ = H+, Na+, K+, Rb+, Cs+ or NH4+.