title: Solution-processable donor-acceptor polymers with modular electronic properties and very narrow bandgaps.
abstract: Bridgehead imine-substituted cyclopentadithiophene structural units, in combination with highly electronegative acceptors that exhibit progressively delocalized π-systems, afford donor-acceptor (DA) conjugated polymers with broad absorption profiles that span technologically relevant wavelength (λ) ranges from 0.7 < λ < 3.2 μm. A joint theoretical and experimental study demonstrates that the presence of the cross-conjugated substituent at the donor bridgehead position results in the capability to fine-tune structural and electronic properties so as to achieve very narrow optical bandgaps (Eg (opt) < 0.5 eV). This strategy affords modular DA copolymers with broad- and long-wavelength light absorption in the infrared and materials with some of the narrowest bandgaps reported to date.
authors: Materials Chemistry Department, Sandia National Laboratories, Livermore, CA, 94551, USA.
authors: Michael E
authors: ME
authors: Foster
authors: Benjamin A
authors: BA
authors: Zhang
authors: Dustin
authors: D
authors: Murtagh
authors: Yi
authors: Y
authors: Liu
authors: Matthew Y
authors: MY
authors: Sfeir
authors: Bryan M
authors: BM
authors: Wong
authors: Jason D
authors: JD
authors: Azoulay
mesh_terms: D003517:Cyclopentanes / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011789:Quantum Theory; D012666:Semiconductors; D012996:Solutions / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry
chemical_list: D003517:Cyclopentanes; D011108:Polymers; D012996:Solutions; D013876:Thiophenes
keywords: density functional calculations; donor-acceptor systems; polymerization; polymers; semiconductors