Charge and spin transport in a metal-semiconductor heterostructure with   double Schottky barriers
  Taking into account the available experimental results, we model the electronic properties and current-voltage characteristics of a ferromagnet-semiconductor junction. The Fe/GaAs interface is considered as a Fe/(i-GaAs)/n+-GaAs/n-GaAs multilayer structure with the Schottky barrier. We also calculate numerically the current-voltage characteristics of a double-Schottky-barrier structure Fe/GaAs/Fe, which are in agreement with available experimental data. For this structure, we have estimated the spin current in the GaAs layer, which characterizes spin injection from the ferromagnet to the semiconductor. 
S. Wolski, C. Jasiukiewicz, V. K. Dugaev, J. Barnas, T. Slobodskyy, W.   Hansen
cond-mat.mtrl-sci