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Article Citation - WoS: 8Citation - Scopus: 9Structural and Optoelectronic Properties of Cds/Y Thin Films(Elsevier Science Sa, 2019) Qasrawi, A. F.; Abed, Tamara Y.In the current study, the structural, optical, photoelectrical and electrical properties of CdS/Y/CdS thin films are investigated. The current design include the evaporation of a layer of 70 nm thick yttrium between two layers of CdS. Each CdS layer is of thickness of 500 nm. It is observed that the yttrium slab increased the microstrain, defect density, stacking faults and decreased the grain size and redshifts the indirect allowed transitions energy band gap of CdS. In addition an enhancement by similar to 5 times in the light absorbability is detected at 1.74 eV. The enhanced absorbance results in increasing the photocurrent by similar to 21 times and changed the recombination mechanism from a trap assisted recombination to supralinear recombination mechanisms. Moreover, the ac signal analysis in the frequency domain of 10-1800 MHz has shown that the yttrium forces the CdS to exhibit negative capacitance effect and make it behave as band stop filter with notch frequency of 1520 MHz. The quality of the CdS/Y/CdS films as microwave cavities are screened by the evaluation of the return loss which revealed good features of the nanostructured films as microwave receivers.Article Citation - WoS: 7Citation - Scopus: 7Structural and Dielectric Properties of Ba1-x< Solid Solutions(Wiley-v C H verlag Gmbh, 2021) Qasrawi, A. F.; Sahin, Ethem Ilhan; Abed, Tamara Y.; Emek, MehribanHerein, lanthanum doping effects on the structural, dielectric, and electrical properties of Ba1-xLax(Zn1/3Nb2/3)O-3 (BZN) solid solutions are focused upon. The La contents which are varied in the range of 0.02-0.20 exhibit a solubility limit of x = 0.02. Although minor phases of Ba5Nb4O15 and Ba3LaNb3O12 appear for samples doped with La contents of x = 0.05 and x = 0.10, they play no remarkable role for the enhanced structural and dielectric properties of BZN. The La doping content of x = 0.02 succeeds in increasing the crystallite size by 51.16% and lowering the microstrain by 34.18% and defect concentration by 63.10%. La-doped BZN ceramics display higher values of relative density and electrical conductivity. The analyses of the dielectric spectra as a function of temperature display dielectric relaxation behavior above 120 degrees C. In the temperature range of 20-120 degrees C, La doping changes the temperature coefficient of dielectric constants from +30 ppm degrees C-1 in pure samples to -341 ppm degrees C-1 in samples doped with La contents of x = 0.10. The enhancements in structural parameters, density values, and dielectric responses that are achieved via La doping make BZN ceramics more suitable for electronic device fabrication.
