title: New form of an old natural dye: bay-annulated indigo (BAI) as an excellent electron accepting unit for high performance organic semiconductors.
abstract: A novel electron acceptor was synthesized from one-step functionalization of the readily available indigo dye. The resulting bay-annulated indigo (BAI) was utilized for the preparation of a series of novel donor-acceptor small molecules and polymers. As revealed experimentally and by theoretical calculations, substituted BAIs have stronger electron accepting characteristics when compared to several premier electron deficient building blocks. As a result, the donor-acceptor materials incorporating BAI acceptor possess low-lying LUMO energy levels and small HOMO-LUMO gaps. In situ grazing incidence wide-angle X-ray scattering studies of the thin films of BAI donor-acceptor polymers indicated improved crystallinity upon thermal treatment. Field effect transistors based on these polymers show excellent ambipolar transporting behavior, with the hole and electron mobilities reaching 1.5 and 0.41 cm(2) V(-1) s(-1), respectively, affirming BAI as a potent electron accepting unit for high performance organic electronic materials.
authors.affiliation: The Molecular Foundry and ‡Materials Sciences Division, Lawrence Berkeley National Laboratory , One Cyclotron Road, Berkeley, California 94720, United States.
authors.forename: Bo
authors.initials: B
authors.lastname: He
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Pun
authors.forename: Danylo
authors.initials: D
authors.lastname: Zherebetskyy
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Liana M
authors.initials: LM
authors.lastname: Klivansky
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: McGough
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Zhang
authors.forename: Kelvin
authors.initials: K
authors.lastname: Lo
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Russell
authors.forename: Linwang
authors.initials: L
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu