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We discuss methods for imaging the nonequilibrium spin polarization of electrons in Fe/GaAs spin transport devices. Both optically and electrically injected spin distributions are studied by scanning magneto-optical Kerr rotation microscopy. Related methods are used to demonstrate electrical spin detection of optically injected spin-polarized currents. Dynamical properties of spin transport are inferred from studies based on the Hanle effect, and the influence of strain on spin transport data in these devices is discussed. [ABSTRACT FROM AUTHOR]

Ternary Zn1-xCdxO films were grown on (0001) sapphire substrates by pulsed laser deposition. The energy band gap of Zn1-xCdxO films decreases with increasing Cd content. An increase of Cd content also leads to the emission broadening, absorption edge broadening, and crystallinity degradation. The absorption edge and ultraviolet emission energy shift to lower energy from 3.357 eV to 3.295 eV and 3.338 eV to 3.157 eV, respectively, with increasing Cd content from 0.3% to 3% at 4 K. The Stokes’ shift between the absorption and emission is observed and that indicates the increase of exciton localization with Cd content. [ABSTRACT FROM AUTHOR]