Electrical spin injection from Fe into GaAs at room temperature

Injection of spin-polarized electrons is observed at a ferromagnet–semiconductor interface by analyzing the electroluminescence signal of a GaAs/(In,Ga)As light emitting diode covered with Fe. The circular polarization degree of the light emission at room temperature reveals a spin injection efficiency of at least 2% from Fe into GaAs. The underlying injection mechanism is explained in terms of a tunneling process.