Efficient Spin Injection into Silicon and the Role of the Schottky Barrier

Abstract

Implementing spin functionalities in Si, and understanding the fundamental processes of spin injection and detection, are the main challenges in spintronics. Here we demonstrate large spin polarizations at room temperature, 34% in n-type and 10% in p-type degenerate Si bands, using a narrow Schottky and a SiO2 tunnel barrier in a direct tunneling regime. Furthermore, by increasing the width of the Schottky barrier in non-degenerate p-type Si, we observed a systematic sign reversal of the Hanle signal in the low bias regime. This dramatic change in the spin injection and detection processes with increased Schottky barrier resistance may be due to a decoupling of the spins in the interface states from the bulk band of Si, yielding a transition from a direct to a localized state assisted tunneling. Our study provides a deeper insight into the spin transport phenomenon, which should be considered for electrical spin injection into any semiconductor.

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Cited by in corpus (14)

• Room Temperature Electrical Detection of Spin Polarized Currents in Topological Insulators
• Tunnel Magnetoresistance with Atomically Thin Two-Dimensional Hexagonal Boron Nitride Barriers
• Origin and evolution of surface spin current in topological insulators
• Spin Transport and Precession in Graphene measured by Nonlocal and Three-Terminal Methods
• Hanle-effect measurements of spin injection from Mn5Ge3C0.8/Al2O3-contacts into degenerately doped Ge channels on Si
• Spin field-effect transistor action via tunable polarization of the spin injection in a Co/MgO/graphene contact
• Spin phonon interactions and magneto-thermal transport behavior in p-Si
• Self-consistent model of spin accumulation magnetoresistance in ferromagnet-insulator-semiconductor tunnel junctions
• Thermal Creation of Electron Spin Polarization in n-Type Silicon
• Generation and detection of dissipationless spin current in MgO/Si bilayer
• Spin mediated enhanced negative magnetoresistance in Ni80Fe20 and p-silicon bilayer
• Non-linear spin transport in a rectifying ferromagnet/semiconductor Schottky contact
• Evolution of the magnetoresistance lineshape with temperature and electric field across Nb-doped SrTiO${}_3$ interface
• Enhanced Tunnel Spin Injection into Graphene using Chemical Vapor Deposited Hexagonal Boron Nitride