Interband spectra of As2S3 and As2Se3 crystals and glasses

Spectroscopical Study of Amorphous AsSe : Sn Films

“…1) films in the photon energy range 2.2 to 6.2 eV show a wide double peak as well as some weaker peculiarities. This form of the spectra is in agreement with the picture known from the literature for the glass of stoichiometric composition As 2 Se 3 (wide double peak with weak structure at 3.2, 3.6 and 5.3 eV) [11,12]. According to band structure calculation in tight-binding approximation [13] the states near the valence band edge of As 2 Se 3 are predominantly on the chalcogen lone-pair p orbital (low energy side of the reflectivity peak in Fig.…”

Highly Anisotropic Mechanical and Optical Properties of 2D Layered As2S3 Membranes

“…We have also performed photodegradation tests by analyzing the Raman spectrum of the 354–358 cm –1 modes under a set of laser powers. Although As 2 S 3 is known to transmit infrared well, approaching the band gap of the material (∼2.6 eV , ) with excessive light can convert the crystal to its amorphous state, thus locally destroying the crystallinity of the flake (see SI 1). Taking this into account, we further used flakes of thicknesses t > 8 nm and a corresponding low power of the incident laser light to minimize damage to the suspended As 2 S 3 membranes.…”

“…These mechanical properties make As 2 S 3 an interesting alternative to black phosphorus for applications in flexible strain-dependent optoelectronical devices, while stability in air makes it a promising material for further integration into optomechanical nanodevices as well as for research of anisotropic nonlinear mechanics in the 2D limit. We also believe that, due to its high flexibility − and pronounced optoelectronic properties, , As 2 S 3 has perspectives to find applications in atomically thin optical waveplates and to become an interesting candidate material for polarization-sensitive flexible photoconductors , and acousto-optic modulators …”

Compositional Dependence of Infrared Transmission in Ge‐Based Chalcogenide Glasses

“…Provided that the Kramers–Kronig analysis is properly accommodated, vibrational spectrum of a given glass measured via reflectance spectroscopy across the far‐infrared wavelengths where the fundamental vibrational transitions occur would give information as to refractive index dispersion in a straightforward way. [ 19–21 ] In our attempts to measure either absorption or reflection spectra over such far‐infrared wavelengths, spectral signal‐to‐noise ratios were too poor to obtain a reasonably good spectral line shape. Instead, in this study, vibrational spectrum probed via spontaneous Raman scatterings is presumed to reveal a basic information related with fundamental vibrational quanta of ChGs.…”