I. Ivan

Surface deformations and amplitude-phase recording in chalcogenide nanolayered structures

Abstract Enhanced intermixing, induced by a laser beam, has been recently observed in amorphous Se/As2S3 and similar multilayers. We report on the experimental observation of the overall change of thickness due to the light-stimulated interdiffusion and present a model of this process. This offers a new mechanism of optical recording in light sensitive chalcogenides. The recording efficiency depends on the thickness ratio of the component layers and on the modulation period of the multilayer.

Enhancement of photoluminescence intensity by photoinduced interdiffusion in nanolayered a-Se∕As2S3 films

Optical parameters of chalcogenide glass multilayers with 12–15 nm modulation lengths prepared by thermal evaporation can be changed by laser irradiation. Photoluminescence sPLd studies were carried out on such nonirradiated and irradiated multilayered samples of

Nonlinear Photo-Diffusion in Amorphous Chalcogenide Multilayers

a-Se / As_2S_3

Surface Transformations and Growth of Nanocrystals on Au-covered GaAs Crystals

(sublayer thickness of a-Se is 4–5 nm for one set of samples and 1–2 nm for the other set. However

Stimulated interdiffusion and optical recording in amorphous chalcogenide nanomultilayers

As_2S_3

Metal diffusion and surface pattern formation on GaAs and As/sub 2/S/sub 3/ semiconductors

sublayer thickness is 11–12 nm for both sets of samples.) PL intensity can be increased by several orders of magnitude by reducing the Se well layer slower band gapd thickness and can be further increased by irradiating the samples with appropriate wavelengths in the range of the absorption edge. The broadening of luminescence bands takes place either with a decrease in Se layer thickness or with irradiation. The former is due to the change in interface roughness and defects because of the enhanced structural disorder while the latter is due to photoinduced interdiffusion. The photoinduced interdiffusion creates defects at the interface between Se and

Multipurpose 14.5 GHz ECR ion source: Special features and application for surface modification

As_2S_3

Deuteron irradiation induced changes in amorphous AsSe films

by forming an As–Se–S solid solution. From the deconvoluted PL spectrum, it is shown that the peak PL intensity, full width half maximum, and the PL quantum efficiency of particular defects giving rise to PL, can be tuned by changing the sublayer thickness or by interdiffusion.

Light and ion induced interdiffusion in amorphous chalcogenide nanomultilayers

Enhanced intermixing, induced by a laser beam, has been recently observed in amorphous Se/As2S3 and similar multilayers. We report a model, based on the concept of thermal spikes, which can consistently describe experimental observations. The concentration dependence of the light absorption properties causes the photo-stimulated diffusion to be non-linear even when a concentration independent coefficient of thermo-stimulated diffusion is assumed.

Effect of pressure on photo-induced interdiffusion in amorphous chalcogenide nanomultilayers

We present a simple method of nanocrystal growth during the heating of Au-covered GaAs single crystals in a closed quartz ampoule, previously evacuated to 10-1 Pa. The process is the final stage of surface transformations in such crystals which include the disruption of initially continuous, 50 nm thick Au layer and formation of Au-particle fractals in the relatively low 300-500 °C temperature range and a next step, when a variety of crystalline nanowires and even nanotubes grows on the crystal surface during the further short-period heating up to 550-650 °C. These nanostructures were identified by SEM and TEM measurements as b-Ga2O3 and a non-stoichiometric arsenic oxide. It is supposed that the growth of few nanometer thick arsenic oxide tubes follows the vapour-solid mechanism, whereas the catalytic Au-metal growth of thicker b-Ga2O3 nanowires was dominated by the vapour-liquid-solid mechanism.