title: Rigid, Conjugated Macrocycles for High Performance Organic Photodetectors.
abstract: Organic photodetectors (OPDs) are attractive for their high optical absorption coefficient, broad wavelength tunability, and compatibility with lightweight and flexible devices. Here we describe a new molecular design that enables high performance organic photodetectors. We use a rigid, conjugated macrocycle as the electron acceptor in devices to obtain high photocurrent and low dark current. We make a direct comparison between the devices made with the macrocyclic acceptor and an acyclic control molecule; we find that the superior performance of the macrocycle originates from its rigid, conjugated, and cyclic structure. The macrocycle's rigid structure reduces the number of charged defects originating from deformed sp2carbons and covalent defects from photo/thermoactivation. With this molecular design, we are able to suppress dark current density while retaining high responsivity in an ultrasensitive nonfullerene OPD. Importantly, we achieve a detectivity of ∼1014Jones at near zero bias voltage. This is without the need for extra carrier blocking layers commonly employed in fullerene-based devices. Our devices are comparable to the best fullerene-based photodetectors, and the sensitivity at low working voltages (<0.1 V) is a record for nonfullerene OPDs.
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Boyuan
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: M Tuan
authors.initials: MT
authors.lastname: Trinh
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Brandon
authors.initials: B
authors.lastname: Fowler
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Melissa
authors.initials: M
authors.lastname: Ball
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Qizhi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Fay
authors.initials: F
authors.lastname: Ng
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Steigerwald
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: X-Y
authors.identifier: 0000-0002-2090-8484
authors.initials: XY
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Colin
authors.identifier: 0000-0002-0384-5493
authors.initials: C
authors.lastname: Nuckolls
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhong