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Article Citation - Scopus: 1Samarium and Yttrium Doping Induced Phase Transitions and Their Effects on the Structural, Optical and Electrical Properties of Nd2sn2< Ceramics(Iop Publishing Ltd, 2019) Saleh, Adli A.; Qasrawi, A. F.; Hamamera, Hanan Z.; Khanfar, Hazem K.; Yumusak, G.In this work, the effects of Sm+3 and Y+3 doping onto the structural, optical and electrical properties of Nd2Sn2O7 are investigated. An atomic content of 3.49% and 4.29% of Sm and Y, respectively, were sufficient to alter the physical properties of the Nd2Sn2O7. Particularly, the Y+3 ionic substitution decreased the lattice constant, narrows the energy band gap, changed the conductivity type from n- to p- type and increased the electrical conductivity by 73 times without changing the cubic nature of structure of the pyrochlore ceramics. On the other hand, Sm+3 ionic substitutions changed the cubic structure to hexagonal or trigonal and forced optical transitions in the infrared range of light. The energy band gap shrunk from 3.40 to 1.40 eV, the defect density is reduced and the electrical conductivity increased by 47 times via Sm doping. These doping agents' makes the neodymium stannate pyrochlore ceramics more appropriates for optoelectronic applications.Article Citation - WoS: 2Citation - Scopus: 1Hydrogen Implantation Effects on the Electrical and Optical Properties of Inse Thin Films(Tubitak Scientific & Technological Research Council Turkey, 2012) Qasrawi, Atef Fayez; Ilaiwi, Khaled Faysal; Polimeni, AntonioThe effects of hydrogen ion implantation on the structural, electrical and optical properties of amorphous InSe thin films have been investigated. X-ray diffraction analysis revealed no change in the structure of the films. An implantation of 7.3 x 10(18) ions/cm(2) decreased the electrical conductivity by three orders of magnitude at 300 K. Similarly, the conductivity activation energy, which was calculated in the temperature range of 300-420 K, decreased from 210 to 78 meV by H-ion implantation. The optical measurements showed that the direct allowed transitions energy band gap of amorphous InSe films has decreased from 1.50 to 0.97 eV by implantation. Furthermore, significant decreases in the dispersion and oscillator energy, static refractive index and static dielectric constants are also observed by hydrogen implantation.Article Citation - WoS: 4Citation - Scopus: 4Electrical, Optical and Photoconductive Properties of Poly(dibenzo-18(Wiley-v C H verlag Gmbh, 2004) Qasrawi, AF; Cihaner, A; Önal, AMTo investigate the energy levels, absorption bands, band gap, dominant transport mechanisms, recombination mechanisms and the free carrier life time behavior of poly-dibenzo-18-crown-6, poly-DB18C6, films, the dark electrical conductivity in the temperature range of 200-550 K, the absorbance and photocurrent spectra, the photocurrent -illumination intensity and time dependence at 300 K were studied. The dark electrical conductivity measurements revealed the existence of three energy levels located at 0.93, 0.32 and 0.76 eV below the tails of the conduction band. The main transport mechanism in the dark was found to be due to the thermal excitation of charge carriers and the variable range hopping above and below 260 K, respectively. The photocurrent and absorbance spectra reflect a band gap of 3.9 eV. The photocurrent -illumination intensity dependence reflects the sublinear, linear and supralinear characters indicating the decrease, remaining constant and increase in the free electron life time that in turn show the bimolecular, strong and very strong recombination characters at the surface under the application of low, moderate and high illumination intensity, respectively. A response time of 25.6 s was calculated from the decay Of I-ph-time dependence. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
