Ambipolar doping in quasifree epitaxial graphene on SiC(0001) controlled by Ge intercalation
(2011) In Physical Review B (Condensed Matter and Materials Physics) 84(12).- Abstract
- The electronic structure of decoupled graphene on SiC(0001) can be tailored by introducing atomically thin layers of germanium at the interface. The electronically inactive (6 root 3 x 6 root 3)R30 degrees reconstructed buffer layer on SiC(0001) is converted into quasi-free-standing monolayer graphene after Ge intercalation and shows the characteristic graphene pi bands as displayed by angle-resolved photoelectron spectroscopy. Low-energy electron microscopy (LEEM) studies reveal an unusual mechanism of the intercalation in which the initial buffer layer is first ruptured into nanoscopic domains to allow the local in-diffusion of germanium to the interface. Upon further annealing, a continuous and homogeneous quasifree graphene film... (More)
- The electronic structure of decoupled graphene on SiC(0001) can be tailored by introducing atomically thin layers of germanium at the interface. The electronically inactive (6 root 3 x 6 root 3)R30 degrees reconstructed buffer layer on SiC(0001) is converted into quasi-free-standing monolayer graphene after Ge intercalation and shows the characteristic graphene pi bands as displayed by angle-resolved photoelectron spectroscopy. Low-energy electron microscopy (LEEM) studies reveal an unusual mechanism of the intercalation in which the initial buffer layer is first ruptured into nanoscopic domains to allow the local in-diffusion of germanium to the interface. Upon further annealing, a continuous and homogeneous quasifree graphene film develops. Two symmetrically doped (n- and p-type) phases are obtained that are characterized by different Ge coverages. They can be prepared individually by annealing a Ge film at different temperatures. In an intermediate-temperature regime, a coexistence of the two phases can be achieved. In this transition regime, n-doped islands start to grow on a 100-nm scale within p-doped graphene terraces as revealed by LEEM. Subsequently, the n islands coalesce but still adjacent terraces may display different doping. Hence, lateral p-n junctions can be generated on epitaxial graphene with their size tailored on a mesoscopic scale. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2186707
- author
- Emtsev, Konstantin V. ; Zakharov, Alexei LU ; Coletti, Camilla ; Forti, Stiven and Starke, Ulrich
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review B (Condensed Matter and Materials Physics)
- volume
- 84
- issue
- 12
- article number
- 125423
- publisher
- American Physical Society
- external identifiers
-
- wos:000294777400016
- scopus:80053922789
- ISSN
- 1098-0121
- DOI
- 10.1103/PhysRevB.84.125423
- language
- English
- LU publication?
- yes
- id
- ff00dc18-3c5a-4d2c-b460-e9241d23ae94 (old id 2186707)
- date added to LUP
- 2016-04-01 12:55:45
- date last changed
- 2022-04-21 18:44:16
@article{ff00dc18-3c5a-4d2c-b460-e9241d23ae94,
abstract = {{The electronic structure of decoupled graphene on SiC(0001) can be tailored by introducing atomically thin layers of germanium at the interface. The electronically inactive (6 root 3 x 6 root 3)R30 degrees reconstructed buffer layer on SiC(0001) is converted into quasi-free-standing monolayer graphene after Ge intercalation and shows the characteristic graphene pi bands as displayed by angle-resolved photoelectron spectroscopy. Low-energy electron microscopy (LEEM) studies reveal an unusual mechanism of the intercalation in which the initial buffer layer is first ruptured into nanoscopic domains to allow the local in-diffusion of germanium to the interface. Upon further annealing, a continuous and homogeneous quasifree graphene film develops. Two symmetrically doped (n- and p-type) phases are obtained that are characterized by different Ge coverages. They can be prepared individually by annealing a Ge film at different temperatures. In an intermediate-temperature regime, a coexistence of the two phases can be achieved. In this transition regime, n-doped islands start to grow on a 100-nm scale within p-doped graphene terraces as revealed by LEEM. Subsequently, the n islands coalesce but still adjacent terraces may display different doping. Hence, lateral p-n junctions can be generated on epitaxial graphene with their size tailored on a mesoscopic scale.}},
author = {{Emtsev, Konstantin V. and Zakharov, Alexei and Coletti, Camilla and Forti, Stiven and Starke, Ulrich}},
issn = {{1098-0121}},
language = {{eng}},
number = {{12}},
publisher = {{American Physical Society}},
series = {{Physical Review B (Condensed Matter and Materials Physics)}},
title = {{Ambipolar doping in quasifree epitaxial graphene on SiC(0001) controlled by Ge intercalation}},
url = {{http://dx.doi.org/10.1103/PhysRevB.84.125423}},
doi = {{10.1103/PhysRevB.84.125423}},
volume = {{84}},
year = {{2011}},
}