INFLUENCE OF THE ELECTRICAL FIELD ON THE FORMATION PROCESS OF HOLOGRAPHIC DIFFRACTION GRATINGS (HDG) IN VITREOUS CHALCOGENIDE SEMICONDUCTORS

The influence of the electrical field on the process of formation of holographic diffraction lattices in vitreous chalcogenide semiconductor (ChVS) layers in the system (As2S3)x(As2Se3)1-x, has been studied. The thin film structures like metal - ChVS-metal, metal - ChVS-dielectric-metal, metal - ChVS-ion electrode, metal - ChVS-dielectric-ion electrode have been investigated. The ionic electrode was created by using a xerographic method. The processes of etching and metallization of holographic diffraction gratings have been also investigated. The surface of holographic gratings has been investigated by atom-force microscopy. It was established, that the electrical field essentially influences the optical and holographic parameters of ChVS structures. The application of the electrical field leads to the increase of regularity and depth of the relief by 25-30 %. In the same time the structure remains constant - quasi sinusoidal. It was shown, that the application of the electrical field to the studied structures leads, also, to the increase of the photosensitivity of ChVS by 1.5-2 times, and of the diffraction efficiency by 2.5-3.5 times. The dynamic range was expanded by 1.5 times, the time necessary for achievement of the diffraction efficiency was reduced by a factor of 2. It was established, that after etching and metallization, the diffraction efficiency of the samples, to which during the process of recording has been applied the electrical field, was higher by 50-200 %, depending on the exposition, in comparison with the case when the diffraction structure has been obtained in the absence of the electrical field. Possible mechanisms of the observed phenomena have been discussed.