title: Making Graphene Nanoribbons Photoluminescent.
abstract: We demonstrate the alignment-preserving transfer of parallel graphene nanoribbons (GNRs) onto insulating substrates. The photophysics of such samples is characterized by polarized Raman and photoluminescence (PL) spectroscopies. The Raman scattered light and the PL are polarized along the GNR axis. The Raman cross section as a function of excitation energy has distinct excitonic peaks associated with transitions between the one-dimensional parabolic subbands. We find that the PL of GNRs is intrinsically low but can be strongly enhanced by blue laser irradiation in ambient conditions or hydrogenation in ultrahigh vacuum. These functionalization routes cause the formation of sp3defects in GNRs. We demonstrate the laser writing of luminescent patterns in GNR films for maskless lithography by the controlled generation of defects. Our findings set the stage for further exploration of the optical properties of GNRs on insulating substrates and in device geometries.
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: B V
authors.initials: BV
authors.lastname: Senkovskiy
authors.affiliation: Department für Chemie, Universität zu Köln , Luxemburger Strasse 116, 50939 Köln, Germany.
authors.forename: M
authors.identifier: 0000-0002-1402-0374
authors.initials: M
authors.lastname: Pfeiffer
authors.affiliation: Department für Chemie, Universität zu Köln , Luxemburger Strasse 116, 50939 Köln, Germany.|Institut für Angewandte Physik der Universität Bonn , Wegeler Strasse 8, 53115 Bonn, Germany.
authors.forename: S K
authors.initials: SK
authors.lastname: Alavi
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Bliesener
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Zhu
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Michel
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.|St. Petersburg State University , Ulianovskaya 1, St. Petersburg 198504, Russia.|IFW Dresden , P.O. Box 270116, Dresden D-01171, Germany.
authors.forename: A V
authors.initials: AV
authors.lastname: Fedorov
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: R
authors.initials: R
authors.lastname: German
authors.affiliation: Department für Chemie, Universität zu Köln , Luxemburger Strasse 116, 50939 Köln, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Hertel
authors.affiliation: Department of Chemistry, University of California at Berkeley , Tan Hall 680, Berkeley, California 94720, United States.
authors.forename: D
authors.initials: D
authors.lastname: Haberer
authors.affiliation: Elettra Sincrotrone Trieste , Strada Statale 14 km 163.5, 34149 Trieste, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Petaccia
authors.affiliation: Department of Chemistry, University of California at Berkeley , Tan Hall 680, Berkeley, California 94720, United States.
authors.forename: F R
authors.identifier: 0000-0003-4723-3111
authors.initials: FR
authors.lastname: Fischer
authors.affiliation: Department für Chemie, Universität zu Köln , Luxemburger Strasse 116, 50939 Köln, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Meerholz
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: P H M
authors.initials: PHM
authors.lastname: van Loosdrecht
authors.affiliation: Department für Chemie, Universität zu Köln , Luxemburger Strasse 116, 50939 Köln, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Lindfors
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: A
authors.identifier: 0000-0003-2448-6060
authors.initials: A
authors.lastname: Grüneis
keywords: Graphene; Raman; defects; hydrogenation; nanoribbons; photoluminescence