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Title: Probing electronic lifetimes and phonon anharmonicities in high-quality chemical vapor deposited graphene by magneto-Raman spectroscopy

We present a magneto-Raman study on high-quality single-layer graphene grown by chemical vapor deposition (CVD) that is fully encapsulated in hexagonal boron nitride by a dry transfer technique. By analyzing the Raman D, G, and 2D peaks, we find that the structural quality of the samples is comparable with state-of-the-art exfoliated graphene flakes. From B-field dependent Raman measurements, we extract the broadening and associated lifetime of the G peak due to anharmonic effects. Furthermore, we determine the decay width and lifetime of Landau level (LL) transitions from magneto-phonon resonances as a function of laser power. At low laser power, we find a minimal decay width of 140 cm{sup −1} highlighting the high electronic quality of the CVD-grown graphene. At higher laser power, we observe an increase of the LL decay width leading to a saturation, with the corresponding lifetime saturating at a minimal value of 18 fs.
Authors:
;  [1] ;  [2] ; ; ; ;  [1] ;  [1] ;  [3] ; ;  [4]
  1. JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen (Germany)
  2. (PGI-9), Forschungszentrum Jülich, 52425 Jülich (Germany)
  3. (Luxembourg)
  4. National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)
Publication Date:
OSTI Identifier:
22486204
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BORON NITRIDES; CHEMICAL VAPOR DEPOSITION; GRAPHENE; LASERS; LIFETIME; PHONONS; RAMAN SPECTROSCOPY; WIDTH