Mass transport in amorphous As2S3 films due to directional light scattering under illumination by an oblique tightly focused beam

Raman evidence for the oxidation of amorphous As2(SexS1–x)3 film surfaces under visible light

“…Photoinduced mass transport upon illumination at λ exc , P exc , and duration values of the same order was earlier reported for amorphous arsenic chalcogenides, revealing the formation of similar pits in the laser spot with depth up to 500-600 nm as well as noticeable protrusions with lateral size up to several micrometers [4, 13-15, 28, 43]. Despite a temptation to ascribe the drastic changes of the amorphous film surface to illumination-induced heating, the formation of the pit and the surrounding circular protrusion are generally attributed to a nonthermal mechanism related to photosoftening (photofluidisation) [1,3,4,28,43]. Local structural changes in amorphous chalcogenides upon illumination are considered as relaxation events in the vicinity of the atom having absorbed a photon.…”

“…The photofluidisation is revealed as a drastic decrease of the material viscosity and a strongly enhanced diffusion under intense illumination. The lateral mass transport from heavily illuminated towards less illuminated areas can result in the formation of a surface relief on quite a large scale [4]. In amorphous arsenic chalcogenide films doped with Group II or Group III elements the photoenhanced diffusion facilitates aggregation of the dopant atoms with the atoms of the amorphous film network and formation of II-VI or III-V nanocrystals in the illuminated area [12,14,15,28,43].…”

“…Amorphous arsenic chalcogenides are extensively studied due to a variety of photostructural effects resulting in drastic changes of their properties under illumination by light of appropriate energy, intensity, and polarization [1][2][3][4]. The photoinduced effects make these materials suitable for applications in all-optical switching [5,6], waveguides [7], memory devices [8], holographic gratings [6], microstructured optical fibres [9], photoresists [10], substrates for surface-enhanced Raman scattering (SERS) [11], etc.…”

Photoinduced transformations in (As1–xBix)2S3 glass observed by Raman spectroscopy

“…17 Among other photostructural phenomena in amorphous arsenic and germanium chalcogenides, 11,[19][20][21] mass transport induced by above-bandgap or belowbandgap illumination has been extensively studied. [22][23][24][25] A drastic photoinduced decrease of the glass viscosity (photofluidisation) is a nonthermal process and leads to an enhanced diffusion in the material, which can result in the formation of a relief on the surface as well as in a rearrangement of atoms in the glass network. In amorphous As 2 S 3 films doped with Cd or Zn photoenhanced diffusion enabled the dopant atoms, initially randomly distributed in the material, to aggregate together with S atoms, forming CdS or ZnS nanocrystalline phase in an amorphous As 2 S 3 -based matrix.…”

Photo-induced bending of chalcogenide glass fiber

“…It could be assumed as a kind of opto-mechanical effects, which appear in dye-polymers [15][16][17] and chalcogenide glasses. 16,[18][19][20][21] Regarding the latter, Krecmer et al 18,22) have discovered transitory deflection of silicon-nitride AFM cantilevers, which are overlayed by As-S-Se films, upon changing the direction of electric fields of linearly-polarized light. Asao and Tanaka have reproduced the phenomenon using As 2 S 3 (and Se) films deposited on mica substrates.…”