An electronic device with a semiconductor layer of (I) ##STR00001## wherein X is O or NR'; m represents the number of methylenes; M is a conjugated moiety; R and R' are selected from the group consisting of at least one of hydrogen, a suitable hydrocarbon, and a suitable hetero-containing group; a represents the number of 3-substituted thiophene units; b represents the number of conjugated moieties, and n represents the number of polymer repeating units.