Band-structure spin-filtering in vertical spin valves based on chemical vapor deposited WS2
| Autor: | Sophie Collin, Jean-Christophe Charlier, Bernard Servet, Pierre Brus, Karim Bouzehouane, Pierre Seneor, Frédéric Petroff, Mauro Och, Marta Galbiati, Aymeric Vecchiola, Florian Godel, Marie-Blandine Martin, Pawel Palczynski, Odile Bezencenet, Simon M-M Dubois, Victor Zatko, Bruno Dlubak, Cecilia Mattevi |
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| Přispěvatelé: | The Royal Society, Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, Institut de la matière condensée et des nanosciences / Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain = Catholic University of Louvain (UCL), Imperial College London, Thales Research and Technology [Palaiseau], THALES |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Tungsten disulfide General Physics and Astronomy 02 engineering and technology 010402 general chemistry 01 natural sciences chemistry.chemical_compound Condensed Matter::Materials Science Transition metal tungsten disulfide Condensed Matter::Superconductivity spin filtering General Materials Science [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] Nanoscience & Nanotechnology Electronic band structure 2D Spin-½ [PHYS]Physics [physics] spintronics Spin filtering Condensed matter physics Spintronics business.industry General Engineering semiconductor Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology magnetic tunnel junction 0104 chemical sciences Tunnel magnetoresistance Semiconductor chemistry Condensed Matter::Strongly Correlated Electrons 0210 nano-technology business |
| Zdroj: | ACS Nano ACS Nano, American Chemical Society, 2019, 13 (12), pp.14468-14476. ⟨10.1021/acsnano.9b08178⟩ |
| ISSN: | 1936-0851 |
| Popis: | International audience; We report on spin transport in WS2-based 2D-magnetic tunnel junctions (2D-MTJs), unveiling a band structure spin filtering effect specific to the transition metal dichalcogenides (TMDCs) family. WS2 mono-, bi-, and trilayers are derived by a chemical vapor deposition process and further characterized by Raman spectroscopy, atomic force microscopy (AFM), and photoluminescence spec-troscopy. The WS2 layers are then integrated in complete Co/Al2O3 /WS2/Co MTJ hybrid spin-valve structures. We make use of a tunnel Co/Al2O3 spin analyzer to probe the extracted spin-polarized current from the WS2/Co interface and its evolution as a function of WS2 layer thicknesses. For monolayer WS2, our technological approach enables the extraction of the largest spin signal reported for a TMDC-based spin valve, corresponding to a spin polarization of PCo/WS2 = 12%. Interestingly, for bi-and trilayer WS2, the spin signal is reversed, which indicates a switch in the mechanism of interfacial spin extraction. With the support of ab initio calculations, we propose a model to address the experimentally measured inversion of the spin polarization based on the change in the WS2 band structure while going from monolayer (direct bandgap) to bilayer (indirect bandgap). These experiments illustrate the rich potential of the families of semiconducting 2D materials for the control of spin currents in 2D-MTJs. |
| Databáze: | OpenAIRE |
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