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Title: Band alignments in Fe/graphene/Si(001) junctions studied by x-ray photoemission spectroscopy

Abstract

The control of tunnel contact resistance is of primary importance for semiconductor-based spintronic devices. This control is hardly achieved with conventional oxide-based tunnel barriers due to deposition-induced interface states. Manipulation of single 2D atomic crystals (such as graphene sheets) weakly interacting with their substrate might represent an alternative and efficient way to design new heterostructures for a variety of different purposes including spin injection into semiconductors. In the present paper, we study by x-ray photoemission spectroscopy the band alignments and interface chemistry of iron–graphene-hydrogenated passivated silicon (001) surfaces for a low and a high n-doping concentration. We find that the hydrogen passivation of the Si(001) surface remains efficient even with a graphene sheet on the Si(001) surface. For both doping concentrations, the semiconductor is close to flat-band conditions which indicates that the Fermi level is unpinned on the semiconductor side of the Graphene/Si(001):H interface. When iron is deposited on the graphene/Si(001):H structures, the Schottky barrier height remains mainly unaffected by the metallic overlayer with a very low barrier height for electrons, a sought-after property in semiconductor based spintronic devices. Finally, we demonstrate that the graphene layer intercalated between the metal and semiconductor also serves as a protection against iron-silicide formationmore » even at elevated temperatures preventing from the formation of a Si-based magnetic dead layer.« less

Authors:
; ; ; ; ;  [1]
  1. Département Matériaux et Nanosciences, Institut de Physique de Rennes, UMR 6251, CNRS-Université de Rennes 1, Campus de Beaulieu, Bât 11 E, 35042 Rennes Cedex (France)
Publication Date:
OSTI Identifier:
22594392
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONCENTRATION RATIO; CRYSTALS; DIFFUSION BARRIERS; ELECTRONS; FERMI LEVEL; GRAPHENE; INTERFACES; IRON; IRON SILICIDES; LAYERS; OXIDES; PHOTOELECTRON SPECTROSCOPY; PHOTOEMISSION; SEMICONDUCTOR MATERIALS; SILICON; SUBSTRATES; SURFACES; TWO-DIMENSIONAL CALCULATIONS; X RADIATION

Citation Formats

Le Breton, J.-C., E-mail: jean-christophe.lebreton@univ-rennes1.fr, Tricot, S., Delhaye, G., Lépine, B., Turban, P., and Schieffer, P. Band alignments in Fe/graphene/Si(001) junctions studied by x-ray photoemission spectroscopy. United States: N. p., 2016. Web. doi:10.1063/1.4960199.
Le Breton, J.-C., E-mail: jean-christophe.lebreton@univ-rennes1.fr, Tricot, S., Delhaye, G., Lépine, B., Turban, P., & Schieffer, P. Band alignments in Fe/graphene/Si(001) junctions studied by x-ray photoemission spectroscopy. United States. doi:10.1063/1.4960199.
Le Breton, J.-C., E-mail: jean-christophe.lebreton@univ-rennes1.fr, Tricot, S., Delhaye, G., Lépine, B., Turban, P., and Schieffer, P. 2016. "Band alignments in Fe/graphene/Si(001) junctions studied by x-ray photoemission spectroscopy". United States. doi:10.1063/1.4960199.
@article{osti_22594392,
title = {Band alignments in Fe/graphene/Si(001) junctions studied by x-ray photoemission spectroscopy},
author = {Le Breton, J.-C., E-mail: jean-christophe.lebreton@univ-rennes1.fr and Tricot, S. and Delhaye, G. and Lépine, B. and Turban, P. and Schieffer, P.},
abstractNote = {The control of tunnel contact resistance is of primary importance for semiconductor-based spintronic devices. This control is hardly achieved with conventional oxide-based tunnel barriers due to deposition-induced interface states. Manipulation of single 2D atomic crystals (such as graphene sheets) weakly interacting with their substrate might represent an alternative and efficient way to design new heterostructures for a variety of different purposes including spin injection into semiconductors. In the present paper, we study by x-ray photoemission spectroscopy the band alignments and interface chemistry of iron–graphene-hydrogenated passivated silicon (001) surfaces for a low and a high n-doping concentration. We find that the hydrogen passivation of the Si(001) surface remains efficient even with a graphene sheet on the Si(001) surface. For both doping concentrations, the semiconductor is close to flat-band conditions which indicates that the Fermi level is unpinned on the semiconductor side of the Graphene/Si(001):H interface. When iron is deposited on the graphene/Si(001):H structures, the Schottky barrier height remains mainly unaffected by the metallic overlayer with a very low barrier height for electrons, a sought-after property in semiconductor based spintronic devices. Finally, we demonstrate that the graphene layer intercalated between the metal and semiconductor also serves as a protection against iron-silicide formation even at elevated temperatures preventing from the formation of a Si-based magnetic dead layer.},
doi = {10.1063/1.4960199},
journal = {Applied Physics Letters},
number = 5,
volume = 109,
place = {United States},
year = 2016,
month = 8
}
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