Energy exchange between the electrons and phonons is particularly important to electron transport, and understanding
this process will be vital for the realization of future graphene-based electronics. Epitaxial growth is a very promising
approach for practical applications, as it has the ability to prepare graphene on a large scale and supported on a substrate.
However, epitaxially grown graphene is highly inhomogeneous, with variations in the sample thickness occurring over
length scale of a few micrometers. To pave the road for electronic devices based on epitaxial graphene, characterization
methods with high spatial resolution are required. In this paper, we describe transient absorption microscopy as a novel
tool to characterize graphene, and to interrogate the charge carrier dynamics. The carrier cooling exhibited a biexponential
decay that showed a significant dependence on carrier density. The fast and slow relaxation times were
assigned to coupling between electrons and optical phonon modes and the hot phonon effect, respectively. The limiting
value of the slow relaxation time at high pump intensity reflects the lifetime of the optical phonons. Significant spatial
heterogeneity in the dynamics was observed due to differences in coupling between graphene layers and the substrate.
This is attributed to differences in coupling between the graphene and the substrate. These results point to transient
absorption microscopy as a potentially important tool for characterizing graphene.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.