Optical and electrical spin injection in spin-LED

We have fabricated and characterized a spin-LED with a tunnel barrier made of a ferromagnetic metal (Co)/semiconductor (AlGaAs) Schottky junction [Phys. Rev. B 62 (2000) R16267]. Under a longitudinal magnetic field of View the MathML source, we measured a circular polarization degree of the electro-luminescence of ∼4%. Using the electron spin relaxation and recombination times measured by time-resolved photoluminescence, the yield of spin injection through Schottky contact of the spin-LED has been determined. We find η∼30%.