Compositions, methods and polymers

Abstract

A composition comprising a homopolymer or a copolymer comprising bithiophene units for use in, for example, low band gap materials including uses in organic photovoltaic active layers. The band gap and other properties can be engineered by polymerization methods including selection of monomer structure and ratio of monomer components. In addition, a dimer adapted for making alternating copolymers further comprising one first monomer moiety comprising at least one bithiophene moiety compound covalently linked to one second monomer moiety comprising a different bithiophene moiety or at least one moiety that is not a bithiophene. The composition can be copolymerized to form an alternating copolymer that can be further processed to form a polymeric film used in a printed organic electronic device. A series of novel copolymers are designed that would allow fabrication of materials with tailor made electronic and/or mechanical properties that can be easily manipulated through molecules chemical structure and potentially result in long term stability under ambient conditions that can be advantageous for use in organic electronics (e.g., OPVs, OLEDs, OFETs). Improved methods are disclosed for making monomers comprising a benzo[2,1-b:3,4-b']dithiophene moiety that are useful as electronics materials.