10.1021/acsami.9b09681.s001
Marialilia Pea
Marialilia
Pea
Monica De Seta
Monica
De Seta
Luciana Di Gaspare
Luciana
Di Gaspare
Luca Persichetti
Luca
Persichetti
Andrea Maria Scaparro
Andrea Maria
Scaparro
Vaidotas Miseikis
Vaidotas
Miseikis
Camilla Coletti
Camilla
Coletti
Andrea Notargiacomo
Andrea
Notargiacomo
Submicron
Size Schottky Junctions on As-Grown Monolayer
Epitaxial Graphene on Ge(100): A Low-Invasive Scanned-Probe-Based
Study
American Chemical Society
2019
p-type Schottky contact behavior
oxidation configuration
graphene regions
graphene layer
low-invasive processing approach
metal-free graphene monolayer
Characteristic junction parameters
graphene growth process
scanning probe microscopy lithography
Low-Invasive Scanned-Probe-Based Study
acceptor defects
energy barrier height
p-type conversion
heterojunction properties
Submicron Size Schottky Junctions
As-Grown Monolayer Epitaxial Graphene
Schottky barrier
n-type doping
ideality factor values
conductive-atomic force microscopy
Dirac point
Ge semiconductor substrate in
SB devices
Ge substrate
2019-09-11 18:33:20
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Submicron_Size_Schottky_Junctions_on_As-Grown_Monolayer_Epitaxial_Graphene_on_Ge_100_A_Low-Invasive_Scanned-Probe-Based_Study/9807809
We
report on the investigation of the Schottky barrier (SB) formed
at the junction between a metal-free graphene monolayer and Ge semiconductor
substrate in the as-grown epitaxial graphene/Ge(100) system.
In order to preserve the heterojunction properties, we defined submicron
size graphene/Ge junctions using the scanning probe microscopy lithography
in the local oxidation configuration, a low-invasive processing approach
capable of inducing spatially controlled electrical separations among
tiny graphene regions. Characteristic junction parameters were estimated
from <i>I</i>–<i>V</i> curves obtained
using conductive-atomic force microscopy. The current–voltage
characteristics showed a p-type Schottky contact behavior, ascribed
to the n-type to p-type conversion of the entire Ge substrate due
to the formation of a large density of acceptor defects during the
graphene growth process. We estimated, for the first time, the energy
barrier height in the as-grown graphene/Ge Schottky junction (φ<sub>B</sub> ≈ 0.45 eV) indicating an n-type doping of the graphene
layer with a Fermi level ≈ 0.15 eV above the Dirac point. The
SB devices showed ideality factor values around 1.5 pointing to the
high quality of the heterojunctions.