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Amorphous Cd-doped As 2 Se 3 films with nominal Cd contents up to 12 at.% were prepared by thermal evaporation. Atomic force microscopy studies confirm the uniform film structure with surface roughnesses below 1 nm, independent of the Cd content. As shown by energy-dispersive X-ray spectroscopy, the Cd content in the film reveals a strong gradient and decreases with the film depth. For heavily Cd-doped (above 7 at.%) As 2 Se 3 films, Raman features attributed to CdSe longitudinal optical (LO) phonon and its overtone (2LO) are revealed in the Raman spectra as an evidence for the formation of CdSe nanocrystallites in the As 2 Se 3 :Cd film under above-bandgap or below-bandgap laser illumination. The CdSe nanocrystallites undergo tensile strain due to a photoplastic effect in the As 2 Se 3 film, i. e. partial removal of the material from the laser spot. The tensile strain value, estimated from the LO phonon frequency shift, is shown to reach nearly 2 GPa.

The electrical studies of In-doped thin films based glassy As2S3 and As2Se3, determined the energy of activation, the analysis of photovoltaic memory samples.Keywords: chalcogenide glasses, energy activation, modification, thin films.

As2S3 and As2Se3 chalcogenide glasses doped with cadmium were synthesized in quartz ampoules. Thin chalcogenide films based on the synthesized compounds were deposited by thermal vacuum evaporation. Optical transmission spectra of the obtained films were measured and refractive index values were determined. For the films under investigation the energy bandgap, effective dispersion oscillator energy, and dispersion energy values were determined. Based on the material dispersion parameters, ionicity degree was estimated.

Amorphous Zn-doped As2Se3 films with a nominal zinc content x up to 10 at.% were prepared by thermal evaporation. Their structure is characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoemission spectroscopy (XPS), and Raman spectroscopy. The AFM data show a considerable increase of the film surface roughness for films with x > 5 at.%. A strong gradient of the Zn content decreasing into the film depth is confirmed by the EDX and XPS data. Heavily Zn-doped (above 7 at.%) As2Se3 films reveal photostructural changes in the course of the Raman measurements. New Raman features are attributed to TO and LO vibrations of ZnSe nanocrystallites formed in the film under laser illumination. Depending on the laser wavelength and power density, the ZnSe nanocrystallites can experience tensile strain in the film due to a non-thermal photoplastic effect in the As2Se3 film resulting in a partial removal of the material from the laser spot. The tensile strain value, estimated from the TO and LO phonon frequency shift, is shown to reach up to 2.9 GPa.

The mechanism of photoinduced expansion/contraction in glassy As2S3 has a photochemical nature. Photostructural transformation is connected with rearrangement of As4S4 molecules and similar non-stoichiometric compounds, As4S4+x. These molecules are believed to exist in clusters which correspond to the second glass-forming region of As–S systems, including the As56S44 eutectic.

The optical characteristics of thin (∼2-μm-thick) films of As2S3 chalcogenide glass prepared by thermal deposition in vacuum have been determined from the results of multiangle ellipsometric measurements using He-Ne laser radiation (λ = 0.6328 μm), with allowance for weak absorption in this spectral range. Relaxation-induced changes in the optical properties of both freshly prepared (unannealed) and annealed As2S3 films are determined. The possibility of using ellipsometry for the qualitative estimation of the degree of inhomogeneity of the film and its variation in the course of structural transformations during relaxation or under the action of other factors is considered.