Almost Perfect Spin Filtering in Graphene-Based Magnetic Tunnel Junctions.

We report on large spin-filtering effects in epitaxial graphene-based spin valves, strongly enhanced in our specific multilayer case. Our results were obtained by the effective association of chemical vapor deposited (CVD) multilayer graphene with a high quality epitaxial Ni(111) ferromagnetic spin source. We highlight that the Ni(111) spin source electrode crystallinity and metallic state are preserved and stabilized by multilayer graphene CVD growth.

Band-Gap Landscape Engineering in Large-Scale 2D Semiconductor van der Waals Heterostructures.

We present a growth process relying on pulsed laser deposition for the elaboration of complex van der Waals heterostructures on large scales, at a 400 °C CMOS-compatible temperature. Illustratively, we define a multilayer quantum well geometry through successive growths, leading to WSe being encapsulated into WS layers. The structural constitution of the quantum well geometry is confirmed by Raman spectroscopy combined with transmission electron microscopy.

Band-Structure Spin-Filtering in Vertical Spin Valves Based on Chemical Vapor Deposited WS.

We report on spin transport in WS-based 2D-magnetic tunnel junctions (2D-MTJs), unveiling a band structure spin filtering effect specific to the transition metal dichalcogenides (TMDCs) family. WS mono-, bi-, and trilayers are derived by a chemical vapor deposition process and further characterized by Raman spectroscopy, atomic force microscopy (AFM), and photoluminescence spectroscopy. The WS layers are then integrated in complete Co/AlO/WS/Co MTJ hybrid spin-valve structures.