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Article Citation - WoS: 9Citation - Scopus: 8Exploring the Optical Dynamics in the Ito/As2< Interfaces(Springer, 2019) Al Garni, S. E.; Qasrawi, A. F.In this work, the effects of indium tin oxide (ITO) substrates on the structural, compositional, optical dielectric and optical conduction properties of arsenic selenide thin films are investigated. The As2Se3 films which are prepared by the thermal deposition technique under vacuum pressure of 10(-5) mbar exhibit an induced crystallization process, improved stoichiometry, increased optical transmittance in the visible range of light and increased dielectric response in the infrared range of light upon replacement of glass substrates by ITO. The ITO/As2Se3 interfaces exhibit conduction and valence band offset values of 0.46 eV and 0.91 eV, respectively. The experimental optical conductivity spectra are theoretically reproduced with the help of the Drude-Lorentz approach for optical conduction. In accordance with this approach, owing to the improved crystallinity of the arsenic selenide, the deposition of As2Se3 onto ITO substrates increases the drift mobility value from similar to 17.6 cm(2)/Vs to 34.6 cm(2)/Vs. It also reduces the density of free carriers by one order of magnitude. The ITO/As2Se3/C heterojunction devices which are tested as band filters which may operate in the frequency domain of 0.01-3.0 GHz revealed low pass filter characteristics below 0.35 GHz and band pass filter characteristics in the remaining spectral range.Article Citation - WoS: 5Citation - Scopus: 4Nickel Doping Effects on the Structural and Dielectric Properties of Ba(zn1/3< Perovskite Ceramics(Springer, 2021) Qasrawi, A. F.; Sahin, Ethem Ilhan; Emek, MehribanThe effects of nickel doping into Ba(Zn1/3Nb2/3)O-3 (acronym: BZN) ceramics is structurally, morphologically and electrically investigated. The nickel substitution in sites of Zn which was carried out by the solid state reaction technique strongly enhanced the structural, morphological and electrical performances of the BZN. Specifically, while the lattice constant and crystallite sizes increased, the microstrain and the defect density decreased. The relative density of the BZN ceramics increased from 95.40% to 98.24% upon doping of Ni with content of x = 0.05. In addition, the Ni doping increased the values of electrical conductivity without significant changes in the dielectric constant values. It is also observed that the doping the BZN ceramics highly altered the temperature dependent variation of the relative dielectric constant. In the temperature range of 293-473 K, the x = 0.05 Ni doped BZN samples were less sensitive to temperature. The dynamics of the temperature dependent dielectric response is dominated by the coupled defects excitation mechanisms. Both of the temperatures and frequency dependent dielectric constant, dielectric loss and electrical conductivity suggests that the Ni doped Ba(Zn1/3Nb2/3)O-3 ceramics is more appropriate for electronic device fabrication than the pure ones.
