An electronic device containing a thienylene-arylene polymer comprised of a repeating segment containing at least one 2,5-thienylene segment of (I) or (II), and at least one arylene segment of (IIIa), (IIIb), or (IIIc) ##STR1##

wherein each R is independently an alkyl or an alkoxy side chain; R is halogen, alkyl, or alkoxy, and a and b represent the number of R segments or groups, and wherein the number of arylene segments (IIIa), (IIIb), and (IIIc) is from about 1 to about 3.