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Observation of thickness-independent ultrafast relaxation times in MPCVD few-layer graphene

Ribeiro, Tânia M. ; Magalhães, Tiago E.C. ; Kulyk, Bohdan ; Carvalho, Alexandre F. ; Nilsson, Sebastian LU ; Feuk, Henrik LU orcid ; Fernandes, António J.S. ; Costa, Florinda ; Guerreiro, Paulo T. and Crespo, Helder (2025) In Carbon 232.
Abstract

Graphene presents unique optoelectronic properties, making it attractive for the development of a wide range of new and advanced technological applications such as high-speed photodetectors and all-optical modulators. The study and control of the generated carriers in graphene, namely their ultrafast relaxation dynamics, are of great importance for these applications. Here, we report the ultrafast relaxation times of photogenerated carriers in few-layer graphene grown by microwave plasma chemical vapour deposition. Graphene samples with 3, 5 and 6 layers were studied by degenerate femtosecond optical pump-probe spectroscopy. We observed a fast relaxation constant on the order of 120−180fs and a slow relaxation constant below 1 ps,... (More)

Graphene presents unique optoelectronic properties, making it attractive for the development of a wide range of new and advanced technological applications such as high-speed photodetectors and all-optical modulators. The study and control of the generated carriers in graphene, namely their ultrafast relaxation dynamics, are of great importance for these applications. Here, we report the ultrafast relaxation times of photogenerated carriers in few-layer graphene grown by microwave plasma chemical vapour deposition. Graphene samples with 3, 5 and 6 layers were studied by degenerate femtosecond optical pump-probe spectroscopy. We observed a fast relaxation constant on the order of 120−180fs and a slow relaxation constant below 1 ps, associated with carrier-carrier scattering and carrier-phonon scattering processes, respectively. These results suggest that small variations in the number of graphene layers do not affect the dynamics.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Carrier dynamics, Graphene, Microwave plasma chemical vapour deposition, Time-resolved spectroscopy, Ultrafast pump-probe spectroscopy
in
Carbon
volume
232
article number
119700
publisher
Elsevier
external identifiers
  • scopus:85208289507
ISSN
0008-6223
DOI
10.1016/j.carbon.2024.119700
language
English
LU publication?
yes
id
6c45a8eb-1dc1-42ad-bb25-24103cee3db2
date added to LUP
2024-12-03 15:56:36
date last changed
2025-04-04 15:05:13
@article{6c45a8eb-1dc1-42ad-bb25-24103cee3db2,
  abstract     = {{<p>Graphene presents unique optoelectronic properties, making it attractive for the development of a wide range of new and advanced technological applications such as high-speed photodetectors and all-optical modulators. The study and control of the generated carriers in graphene, namely their ultrafast relaxation dynamics, are of great importance for these applications. Here, we report the ultrafast relaxation times of photogenerated carriers in few-layer graphene grown by microwave plasma chemical vapour deposition. Graphene samples with 3, 5 and 6 layers were studied by degenerate femtosecond optical pump-probe spectroscopy. We observed a fast relaxation constant on the order of 120−180fs and a slow relaxation constant below 1 ps, associated with carrier-carrier scattering and carrier-phonon scattering processes, respectively. These results suggest that small variations in the number of graphene layers do not affect the dynamics.</p>}},
  author       = {{Ribeiro, Tânia M. and Magalhães, Tiago E.C. and Kulyk, Bohdan and Carvalho, Alexandre F. and Nilsson, Sebastian and Feuk, Henrik and Fernandes, António J.S. and Costa, Florinda and Guerreiro, Paulo T. and Crespo, Helder}},
  issn         = {{0008-6223}},
  keywords     = {{Carrier dynamics; Graphene; Microwave plasma chemical vapour deposition; Time-resolved spectroscopy; Ultrafast pump-probe spectroscopy}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Carbon}},
  title        = {{Observation of thickness-independent ultrafast relaxation times in MPCVD few-layer graphene}},
  url          = {{http://dx.doi.org/10.1016/j.carbon.2024.119700}},
  doi          = {{10.1016/j.carbon.2024.119700}},
  volume       = {{232}},
  year         = {{2025}},
}