On the structural stability of amorphous Se/CdSe multilayers: a Raman study

Photo- and thermally induced interdiffusion in Se/As2S3 nanomultilayers prepared by pulsed laser deposition and thermal evaporation

“…Few approaches are known for extending investigations of amorphous chalcogenide layers towards the nanostructures, but the nanolayered, superlattice-like structures are the most investigated [1][2][3][4][5][6]. Inserting the light-sensitive amorphous (a) layer, for example the typical model oneSe x Te 1Àx , where 0pxp1-between different barrier layers and changing the modulation period as well as the type of matrix (barriers) new effects are expected: enhanced interdiffusion, simple formation of solid solutions or stimulation of the solid-state reactions, crystallization and phase separation at the interfaces and a complex of related changes of optical and electrical parameters of the structure.…”

“…The enhanced interdiffusion in the a-Se/As 2 S 3 nanomultilayers (NMLs), that can be considered as model ones, results in the giant volume expansion [1,3], so other combinations of materials or the influence of the technology, real structure on the above-mentioned effects should be analyzed. The method of vacuum evaporation of different components and cyclic deposition of nanometer-thick sub-layers onto the same substrate was usually used up to now [4][5][6], but serious problems can arise from the non-stoichiometry of the deposited components due to the evaporation conditions of multicomponent glasses. The thermal evaporation technology is not always applicable for producing barrier layers (especially oxides, organics), while the best and simplest technology for amorphous chalcogenide containing NMLs fabrication must ensure the possibility of simultaneous deposition of chalcogenide and the barrier layers.…”

Photo-induced transformations in chalcogenide nanocomposite layers

“…Special effects, which accompany PST in chalcogenide layers, give new insight into the basic mechanism of structural transformations and are of increasing applied interest: optomechanical and vector effects [7], stimulated volume expansion or contraction [1,3,[8][9][10]. Few approaches are known for extending investigations of amorphous chalcogenide layers towards the nanostructures, especially in the nanolayered, superlattice-like multilayer structures (MLS) [11,12], but the problem of PST dependence on the artificial nanostructuring is still not solved. Inserting the light-sensitive glass, or just amorphous Se into the certain matrix and changing the dimensions of this cluster, as well as the type of matrix, new effects are expected: further growth of the efficiency of volume expansion, stimulation of the solid-state reactions, crystallization.…”

Photo-induced transformations in chalcogenide composite layers

“…The first type PST is well known, results are reviewed in a number of papers (see for example [1][2][3]) but this type of PST still attracts interest, first of all because of the fundamental problems of stability and stimulated structural transformations in amorphous chalcogenide semiconductors. A new approach to the problem of stability in amorphous structures and creation of photo-sensitive media from amorphous chalcogenides is connected to the local atomic structure, especially to the layered, superlattice-like multilayer structures (NLS) [4][5][6], but the problem of PST in nanometer thick layered (nanolayered) structures is complex and still not solved. Investigations are stimulated by the potential applications of such materials for optical recording, especially connected with stimulated volume expansion or contraction, optical memory and fabrication of elements for photonics [7][8][9][10].…”