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.

References in corpus (5)

• Electrical Detection of Spin Transport in Lateral Ferromagnet-Semiconductor Devices
• Electronic measurement and control of spin transport in Silicon
• Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface
• Spin extraction theory and its relevance to spintronics
• Electrical spin injection in p-type Si using Fe/MgO contacts

Cited by in corpus (6)

• Tunnel Magnetoresistance with Atomically Thin Two-Dimensional Hexagonal Boron Nitride Barriers
• 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
• Self-consistent model of spin accumulation magnetoresistance in ferromagnet-insulator-semiconductor tunnel junctions
• Thermal Creation of Electron Spin Polarization in n-Type Silicon
• Enhanced Tunnel Spin Injection into Graphene using Chemical Vapor Deposited Hexagonal Boron Nitride