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.