Patent ID: 6897284

Claim:
A device containing a polythiophene prepared by a metal halide polymerization in an aromatic solvent, and which polythiophene has a number average molecular weight (M n ) of from about 2,000 to about 100,000, and a weight average molecular weight (M w ) of from about 4,000 to about 500,000, both as measured by gel permeation chromatography using polystyrene standards, and which polythiophene is comprised of at least one monomer unit comprising at least one of 2,5-thienylene segment (I), and at least one of 2,5-thienylene segment (II), and a divalent linkage D wherein A is alkyl or alkoxy; B is a halide; and D is a divalent linkage for said (I) and (II).