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

Surface pattern recording in amorphous chalcogenide layers

“…This correlation illustrates the role of the intrinsic electron-hole generation in the writing process, similar to the photo-stimulated structural transformations in amorphous chalcogenides [1]. Direct heating by laser-beam may influence the process only at power densities P > 3 W/cm 2 [15], so that in our experiments with low intensity illumination we were measuring mainly athermal effects.…”

“…The non-linearity of the dependence of the laser [15] as well as of the e-beam stimulated expansion on exposition at high power (current) densities can be attributed to the heating effects. The increase in temperature would influence not only the rate of charge and defect generation, but also the viscosity.…”

Effect of pressure on photo-induced expansion of As0.2Se0.8 layer

“…Free volume creation may be followed by local volume expansion, so the photo-induced expansion can be analyzed from the point of view of free volume change in a disordered material [11]. Analyzing our present and earlier published results on photoinduced expansion [3,5,12] as well as the existing models of photoinduced changes in chalcogenides [1,6,9]we can conclude that the creation of the surface relief due to the illumination consists of two stage. The first one is faster, the second slower.…”

“…In spite of a rather long history of investigations and even some important applications in memory devices the mechanism of these effects is not completely clear, since besides the necessary condition of light interaction with glass and charge generation of the mass transport, shift or diffusion of atoms must occur. Unfortunately, we have only very little information about the light induced atomic transport processes in amorphous chalcogenides [3]. During the last few years several papers presented investigations on surface expansion due to irradiation in different chalcogenide thin films [4].…”