An electronic device containing a polythiophene derived from a monomer segment or monomer segments containing two 2,5-thienylene segments, (I) and (II), and an optional divalent linkage D ##STR00001## wherein A is a side chain; B is hydrogen or a side chain; and D is a divalent linkage, and wherein the number of A-substituted thienylene units (I) in the monomer segments is from about 1 to about 10, the number of B-substituted thienylene units (II) is from 0 to about 5, and the number of divalent linkages D is 0 or 1.