Efficient spin injection into semiconductor from an Fe/GaOx tunnel injector

Abstract

We examined the electrical injection of spin-polarized electrons into a GaAs-based light-emitting diode structure from a Fe/GaOx tunnel injector whose electron-charge injection efficiency was comparable to that of a conventional Fe/n+-AlGaAs ohmic injector. A high circular polarization of electroluminescence up to 20% was observed at 2 K. The combination of effective spin-and charge-injection efficiencies makes GaOx a promising tunnel barrier for GaAs-based spintronic devices.