IMPURITY OF IRON A Y OF IRON ATOMS IN THE VI OMS IN THE VITREOUS ARSENIC TREOUS ARSENIC SELENIDE (As2Se3). ELEC SELENIDE (As2Se3). ELECTRONIC EX TRONIC EXCHANGE BE ANGE BETWEEN CENTERS OF IRON

Iron atoms in vitreous arsenic selenide films form single electron donor centers, while the Fermi level shifts from the middle of the band gap to the bottom of the conduction band with an increase in the iron concentration due to the filling of single electron states of the acceptor type located below the Fermi level The Mössbauer spectroscopy method was used to study the electronic exchange between ionized and neutral centers of iron in the glassy selenide of arsenic

Synthesis and Studies of Electro-Deposited Yttrium Arsenic Selenide Nanofilms for Opto-Electronic Applications

Nanocomposite films grown by incorporating varying concentrations of Yttrium, a d-block rare-earth ion, into the binary chalcogenide Arsenic selenide host matrix is here presented. Films were grown via the wet-chemical electro-deposition technique and characterized for structural, optical, surface morphology, and photoluminescence (PL) properties. The X-ray Diffraction (XRD) result of the host matrix (pristine film) showed films of monoclinic structure with an average grain size of 36.2 nm. The composite films, on the other hand, had both cubic YAs and tetragonal YSe structures with average size within 36.5–46.8 nm. The fairly homogeneous nano-sized films are shown by the Scanning Electron Microscopy (SEM) micrographs while the two phases of the composite films present in the XRD patterns were confirmed by the Raman shifts due to the cleavage of the As-Se host matrix and formation of new structural units. The refractive index peaked at 2.63 within 350–600 nm. The bandgap energy lies in the range of 3.84–3.95 eV with a slight decrease with increasing Y addition; while the PL spectra depict emission bands across the Vis-NIR spectral regions. Theoretically, the density functional theory (DFT) simulations provided insight into the changes induced in the structure, bonding, and electronic properties. Besides reducing the bandgap of the As2Se3, the yttrium addition has induced a lone pair p-states of Se contributing nearby to Fermi energy level. The optical constants, and structural and electronic features of the films obtained present suitable features of film for IR applications as well as in optoelectronics.

Structural and Behavioural Analysis of As2Se3, TeO2, SiC, SiO2 and Si3N4 for Photonic Application

The materials significantly influence the structural, optical and photoelectrical characteristic. Materials such as Arsenic selenide, Tellurite Glass, Silicon carbide, Silicon dioxide and Silicon nitride are investigated through finite element method. The models are established to analyse the structural behaviour of polarization preserving fibre of proposed materials. Photoelectric characteristic determines guided properties of photon particles. Refractive index of the materials influences the properties of photonic crystal fibre. A Polarization Splitter based hexagonal structure is proposed, where inner ring of cladding is in elliptical shape air holes and outer rings are in circular air holes. It provides highly negative dispersion, low confinement loss and high nonlinear coefficient between 1µm to 2µm wide wavelength ranges. The dispersion result shows -2000 db/km-nm at 1.55µm wavelength. Polarization beam splitters photonic crystal fiber characteristics of proposed materials are analysed with same structural parameters.