Bias voltage dependence of the electron spin injection studied in a three-terminal device based on a (Ga,Mn)As/n+-GaAs Esaki diode

We investigated injection of spin polarized electrons in a (Ga,Mn)As/n(+)-GaAs Esaki diode (ED) by using a three-terminal device integrating a (Ga,Mn)As ED and a light emitting diode (LED). Electroluminescence polarization (P-EL) from the LED was measured under the Faraday configuration as a function of bias voltages applied independently to the Esaki diode and to the LED. The maximum P-EL of 32.4% was observed when the valence electrons near the Fermi energy of (Ga,Mn)As are ballistically injected into the LED. (c) 2006 American Institute of Physics.