Research output: Contribution to journal › Article › peer-review
Controlled thermodynamics for tunable electron doping of graphene on Ir(111). / Struzzi, C.; Praveen, C. S.; Scardamaglia, M.; Verbitskiy, N. I.; Fedorov, A. V.; Weinl, M.; Schreck, M.; Grüneis, A.; Piccinin, S.; Fabris, S.; Petaccia, L.
In: Physical Review B, Vol. 94, No. 8, 085427, 25.08.2016.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Controlled thermodynamics for tunable electron doping of graphene on Ir(111)
AU - Struzzi, C.
AU - Praveen, C. S.
AU - Scardamaglia, M.
AU - Verbitskiy, N. I.
AU - Fedorov, A. V.
AU - Weinl, M.
AU - Schreck, M.
AU - Grüneis, A.
AU - Piccinin, S.
AU - Fabris, S.
AU - Petaccia, L.
N1 - Publisher Copyright: © 2016 American Physical Society. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2016/8/25
Y1 - 2016/8/25
N2 - The electronic properties and surface structures of K-doped graphene supported on Ir(111) are characterized as a function of temperature and coverage by combining low-energy electron diffraction, angle-resolved photoemission spectroscopy, and density functional theory (DFT) calculations. Deposition of K on graphene at room temperature (RT) yields a stable (√3×√3) R30° surface structure having an intrinsic electron doping that shifts the graphene Dirac point by ED=1.30eV below the Fermi level. Keeping the graphene substrate at 80 K during deposition generates instead a (2×2) phase, which is stable until full monolayer coverage. Further deposition of K followed by RT annealing develops a double-layer K-doped graphene that effectively doubles the K coverage and the related charge transfer, as well as maximizing the doping level (ED=1.61eV). The measured electron doping and the surface reconstructions are rationalized by DFT calculations. These indicate a large thermodynamic driving force for K intercalation below the graphene layer. The electron doping and Dirac point shifts calculated for the different structures are in agreement with the experimental measurements. In particular, the K4s bands are shown to be sensitive to both the K intercalation and periodicity and are therefore suggested as a fingerprint for the location and ordering of the K dopants.
AB - The electronic properties and surface structures of K-doped graphene supported on Ir(111) are characterized as a function of temperature and coverage by combining low-energy electron diffraction, angle-resolved photoemission spectroscopy, and density functional theory (DFT) calculations. Deposition of K on graphene at room temperature (RT) yields a stable (√3×√3) R30° surface structure having an intrinsic electron doping that shifts the graphene Dirac point by ED=1.30eV below the Fermi level. Keeping the graphene substrate at 80 K during deposition generates instead a (2×2) phase, which is stable until full monolayer coverage. Further deposition of K followed by RT annealing develops a double-layer K-doped graphene that effectively doubles the K coverage and the related charge transfer, as well as maximizing the doping level (ED=1.61eV). The measured electron doping and the surface reconstructions are rationalized by DFT calculations. These indicate a large thermodynamic driving force for K intercalation below the graphene layer. The electron doping and Dirac point shifts calculated for the different structures are in agreement with the experimental measurements. In particular, the K4s bands are shown to be sensitive to both the K intercalation and periodicity and are therefore suggested as a fingerprint for the location and ordering of the K dopants.
UR - http://www.scopus.com/inward/record.url?scp=84985995517&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.94.085427
DO - 10.1103/PhysRevB.94.085427
M3 - Article
AN - SCOPUS:84985995517
VL - 94
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 8
M1 - 085427
ER -
ID: 9225352