We investigate theoretically electrical spin injection at a Schottky contact between a spin-polarized electrode and a nonmagnetic semiconductor. Current and electron density spin polarizations are discussed as functions of barrier energy and semiconductor doping density. The effect of a spin-dependent interface resistance that results from a tunneling region at the contact/semiconductor interface is described. The model can serve as a guide for designing spin-injection experiments with regard to the interface properties and device structure.

• Received 5 April 2002

DOI:https://doi.org/10.1103/PhysRevB.66.113303