Spin-polarized injection through the n-magnetic/p-nonmagnetic semiconductor heterojunction

In this paper, the spin-polarized injection through n-magnetic/p-nonmagnetic semiconductor heterojunction was investigated theoretically. Based on the drift-diffusion theory and continuity equation, a model was established to explain the spin-polarized injection through the magnetic heterojunction. Boundary conditions were determined by analyzing the relations of the quasi-chemical potentials in n and p regions. The distributions of the charge density, spin density and spin-polarization were calculated using this model. The results demonstrate that an effective spin-polarized electric injection through the heterojunction may be achieved without external spin injection or the application of a large bias. The factors affecting the nonequilibrium spin-polarization (NESP) in the nonmagnetic region were also given based on the simulation results