Analysis of effective spin-polarized transport through a ZnO based magnetic p–n junction at room temperature

ZnO based magnetic semiconductors (MSs) are prominent candidates for the spintronic devices because of their high Curie temperatures and low conductance mismatches. In this paper the spin-polarized transport in MS/nonmagnetic semiconductor (NMS) p–n junction is investigated. A model is established based on semiconductor drift–diffusion theory and continuity equation. Boundary conditions are obtained from the quasi-chemical potential (QCP) relations at the junction interface. For a ZnO based magnetic p–n junction, we calculate the distributions of carrier/spin density and spin polarization at room temperature. It is demonstrated that by choosing proper parameters, effective spin-polarized injection from ZnO based MS into ZnO can be achieved at room temperature without external spin-polarized injection (ESPI) or large bias.