Oscillations of induced photopleochroism in ZnO/GaAs heterojunctions

Anisotype and isotype ZnO/GaAs heterojunctions were formed by magnetron sputtering of thin n-ZnO:Al films on epitaxial layers of n- and p-GaAs. It is shown that the heterostructures obtained have a high photosensitivity (similar to5 x 10(3) V/W at 300 K) in a wide spectral range (1.5-3.2 eV), which oscillates due to the radiation interference in thin ZnO films. Under oblique incidence of linearly polarized radiation on a ZnO film, photopleochroism is induced in a heterojunction, whose value oscillates within similar to1-55% at theta = 85degrees. The photopleochroism oscillations are also due to the radiation interference in the ZnO film. It is concluded that the heterojunctions obtained are promising candidates for selective photodetectors of linearly polarized radiation. (C) 2004 MAIKNauka/Interperiodica.