Electronic properties of doped graphene and graphene nanoribbons: Photoemission study.
DIPC Seminars
- Speaker
-
Alexander Fedorov (Univ. Köln and IFW Dresden, Germany and St Petersburg State University, Russia)
- When
-
2016/11/02
13:00 - Place
- Donostia International Physics Center
- Add to calendar
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**Electronic properties of doped graphene and graphene nanoribbons:
Photoemission study**
Alexander Fedorov
Universität zu Köln, Köln Germany, IFW Dresden, Dresden, Germany, St
Petersburg State University, St Petersburg, Russia
Tailoring of the material electronic properties is the key issue for the
developing new generation electronic devices. The unique properties of
graphene and the numerous possibilities for its applications have made it one
of the most promising for the future application. Due to graphene’s simple
structure and the ease by which it can be functionalized chemically to tune
its electronic properties it is a unique platform for both general study and
applications. From one hand atoms and functional chemical groups may be
adsorbed on its surface. From other hand, incorporation of guest atoms, like
boron or nitrogen, into the graphene lattice allows one to modify the type of
conductivity, and to tune the concentration of charge carriers. Such
modifications of electronic structure and physicochemical properties greatly
extend capabilities of the doped graphene use in fuel cells, batteries,
supercapacitors, in oxygen reduction reactions, etc.
Electronically doped graphene is interested from the general point of view
since the phonon-mediated superconductivity just recently has been observed in
the 2D materials, however it is well established in many carbon related
materials. For instance, in 3D analog of graphene – alkali doped graphite.
Therefore heavy electron-doped graphene is a good candidate for observation of
2D conventional superconductivity. By applying in combination photoemission
and photo absorption spectroscopies, we examined both chemical properties and
electron-phonon coupling in doped graphene.
Despite many unique properties and wide range of possible functionalization
conduction properties of the graphene are limiting its application on the
field effect transistors (FET). However the gapless electronic structure can
be easily modified by applying the quantum confinement. Recent progress in the
interface stimulated self-assembling chemical reactions opened an avenue for
production of wide range of graphene nanoribbons (GNRs). Their electronic
properties are governed both by their structural properties (width) and by the
chemical impurities introduced in the graphene lattice or adsorbed on its
surface. Here we show semiconductor – metal transition in the alkali doped 7
atom width GNRs using angular resolved photoemission.