title: Benzotrithiophene versus Benzo/Naphthodithiophene Building Blocks: The Effect of Star-Shaped versus Linear Conjugation on Their Electronic Structures.
abstract: The synthesis, characterization, and optical properties of a novel star-shaped oligothiophene with a central rigid trithienobenzene (BTT) core and diketopyrrolopyrrole (DPP) units are reported and compared with homologous linear systems based on the benzodithiophene (BDT) and the naphthodithiophene (NDT) units end capped with DPPs. This comparison is aimed at elucidating the effect of the star-shaped configuration versus linear conformation on the optical and electrical properties. Electronic and vibrational spectroscopies, together with transient absorption spectroscopy, scanning electronic microscopy, and DFT calculations are used to understand not only the molecular properties of these semiconductors, but also to analyze the supramolecular aggregation in these derivatives. We conclude that although the subject star-shaped derivative is not optimal in terms of π-conjugation, its extended BTT unit significantly favors intermolecular π-stacking interactions, which is interesting for their applications in devices. Field-effect transistors and solar cells were fabricated with these new molecular semiconductors and the performance difference discussed.
authors.affiliation: Department of Organic Chemistry, Complutense University of Madrid, Faculty of Chemistry, Madrid, 28040, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Riaño
authors.affiliation: Department of Physical Chemistry, University of Málaga, Málaga, 29071, Spain.
authors.forename: Iratxe
authors.initials: I
authors.lastname: Arrechea-Marcos
authors.affiliation: Department of Organic Chemistry, Complutense University of Madrid, Faculty of Chemistry, Madrid, 28040, Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: Mancheño
authors.affiliation: Department of Physical Chemistry, University of Málaga, Málaga, 29071, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Mayorga Burrezo
authors.affiliation: Department of Organic Chemistry, Complutense University of Madrid, Faculty of Chemistry, Madrid, 28040, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: de la Peña
authors.affiliation: Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Loser
authors.affiliation: Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA.
authors.forename: Amod
authors.initials: A
authors.lastname: Timalsina
authors.affiliation: Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA.
authors.forename: Antonio
authors.initials: A
authors.lastname: Facchetti
authors.affiliation: Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA. t-marks@northwestern.edu.
authors.forename: Tobin J
authors.initials: TJ
authors.lastname: Marks
authors.affiliation: Department of Physical Chemistry, University of Málaga, Málaga, 29071, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Casado
authors.affiliation: Department of Physical Chemistry, University of Málaga, Málaga, 29071, Spain. teodomiro@uma.es.
authors.forename: J Teodomiro
authors.initials: JT
authors.lastname: López Navarrete
authors.affiliation: Department of Physical Chemistry, University of Málaga, Málaga, 29071, Spain. rocioponce@uma.es.
authors.forename: Rocío
authors.initials: R
authors.lastname: Ponce Ortiz
authors.affiliation: Department of Organic Chemistry, Complutense University of Madrid, Faculty of Chemistry, Madrid, 28040, Spain. segura@ucm.es.
authors.forename: José L
authors.initials: JL
authors.lastname: Segura
keywords: field-effect transistors; oligothiophene; optical properties; semiconductors; solar cells; π-stacking interactions