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. [ABSTRACT FROM AUTHOR]