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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.

An ultrahigh vacuum chemical vapor deposition system suitable for deposition of epitaxial GeSi layers has been constructed. Its reaction chamber is a rectangular quartz tube that is heated by a graphite heater. Using this system, two high-quality structures of Si/Ge0.18 Si0.82/GexSi1-x/Si nMOSFET and n-Si/p+-Ge0.2 Si0.8/n-Si HBT with controllable doping were successfully grown at 600 and 550℃.

Due to the high hole mobility both in the surface strained Si and buried relaxed SiGe channels, we successfully fabricated a novel strained Siyrelaxed SiGe channel PMOSFET on the heterostructure strained Siyrelaxed SiGeystrained Siyrelaxed SiGe buffer layerygrading Si Ge layer, grown by home-made UHVyCVD system, which is commonly used in 1yx x the 'buried' SiGe NMOSFET.This device is easier to integrate with SiGe NMOSFET to form SiGe CMOS, than strained SiGe channel PMOSFET. Then the process is presented. With Vgs=3.5V, the maximum saturated transconductance is found to be twice as large as that of the control Si PMOS, and approximates to that of a traditional strained SiGe channel PMOS.