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We studied oxygen incorporation into ZnTe thin films with oxygen ambient and oxygen plasma during pulsed laser deposition (PLD). The ZnTe layers deposited by oxygen-plasma-assisted PLD under oxygen partial pressures showed the enhancement of visible absorption due to TeO x formation by oxygen incorporation, which was confirmed by X-ray photoelectron spectroscopy measurement. The ZnTe:O thin films grown under oxygen ambient and plasma produced an energy band structure at about 0.5–0.8 eV below the ZnTe band edge, indicating strong radiative properties. The ZnTe:O samples showed the formation of intermediate bands and p-type semiconducting characteristics, which will be useful for intermediate/defect band solar cells.

The new hybrid device consisting of single array of Co nanodots on top of GaMnAs is presented to explore a new functionality of GaMnAs diluted magnetic semiconductor (DMS). Magnetic state of Co dots was observed by magnetic force microscopy (MFM). Magnetoresistance of pure GaMnAs microbridge strongly depends on the orientation of applied magnetic field. Magnetization reversal of the single domain state definitely affects the longitudinal magnetoresistance of GaMnAs. Inhomogeneous magnetic field induced by Co nanodot is a dominant contribution to the resistance change. This field was regarded to act as an effective potential that may affect the spin polarized carriers in GaMnAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Fe-diluted Si alloys grown on p-type Si (100) substrates by pulsed-laser deposition method were studied for tructural, electrical, and magnetic properties. The X-ray diffraction patterns for these alloy samples showed a few of peaks with cubic structures such as FeSi, The manipulation of electron spin in semiconductors with transition metals is very important.The efficiency of electron spin injection is still deficient in major problems as low as a few % for the realization of spin field effect transistors, which is contributed by the conductance mismatch of junctions between metal and semiconductor. Diluted magnetic semiconductor (DMS) is known to be a useful way to