Semiconductor-to-Metal Transition and Quasiparticle Renormalization in Doped Graphene Nanoribbons

Autor(en)

Boris V. Senkovskiy, Alexander V. Fedorov, Danny Haberer, Mani Farjam, Konstantin A. Simonov, Alexei B. Preobrajenski, Niels Mårtensson, Nicolae Atodiresei, Vasile Caciuc, Stefan Blügel, Achim Rosch, Nikolay I. Verbitskiy, Martin Hell, Daniil V. Evtushinsky, Raphael German, Tomas Marangoni, Paul H.M. van Loosdrecht, Felix R. Fischer, Alexander Grüneis

Abstrakt

A semiconductor-to-metal transition in N = 7 armchair graphene nanoribbons causes drastic changes in its electron and phonon system. By using angle-resolved photoemission spectroscopy of lithium-doped graphene nanoribbons, a quasiparticle band gap renormalization from 2.4 to 2.1 eV is observed. Reaching high doping levels (0.05 electrons per atom), it is found that the effective mass of the conduction band carriers increases to a value equal to the free electron mass. This giant increase in the effective mass by doping is a means to enhance the density of states at the Fermi level which can have palpable impact on the transport and optical properties. Electron doping also reduces the Raman intensity by one order of magnitude, and results in relatively small (4 cm(-1)) hardening of the G phonon and softening of the D phonon. This suggests the importance of both lattice expansion and dynamic effects. The present work highlights that doping of a semiconducting 1D system is strikingly different from its 2D or 3D counterparts and introduces doped graphene nanoribbons as a new tunable quantum material with high potential for basic research and applications.

Organisation(en)

Elektronische Materialeigenschaften

Externe Organisation(en)

Universität zu Köln, Saint Petersburg State University, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, University of California, Berkeley, Uppsala University, Lund University, Forschungszentrum Jülich, Lomonosov Moscow State University (MSU), Helmholtz-Zentrum Berlin für Materialien und Energie, Institute for Research in Fundamental Sciences (IPM)

Journal

Advanced Electronic Materials

Band

3

Anzahl der Seiten

8

DOI

https://doi.org/10.1002/aelm.201600490

Publikationsdatum

04-2017

Peer-reviewed

Ja

ÖFOS 2012

103020 Oberflächenphysik, 103018 Materialphysik, 103009 Festkörperphysik

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/8f616fda-e92c-4ee0-9b75-55f5383cd57b