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Article Citation - WoS: 3Citation - Scopus: 3Ytterbium Induced Structural Phase Transitions and Their Effects on the Optical and Electrical Properties of Znpc Thin Films(Springer, 2020) Qasrawi, A. F.; Zyoud, Hadeel M.In this work, the effects of ytterbium substrates of thicknesses of 150 (Yb-150) and 1000 nm (Yb-1000) on the structural, optical and electrical properties of zinc phthalocyanine (ZnPc) are investigated. While the Yb-150/ZnPc exhibited strained monoclinic structure, the Yb-1000/ZnPc thin films are observed to exhibit phase transitions from monoclinic to triclinic structure. Analysis which targeted observatories of the effects of the Yb-150 substrate on the optical properties indicated that the transparent Yb-150 substrate enhanced the light absorbability by more than 11 times at 1.27 eV. On the other hand, the impedance spectroscopy measurements on the nontransparent Yb-1000/ZnPc/Ag sandwiched structures have shown that these devices could exhibit negative capacitance (NC) effect in the frequency domain of 0.244-1.800 GHz. The NC effect is associated with resonance-anti-resonance response at 0.235 and 0.244 GHz, respectively. The structural, optical and electrical properties of the Yb/ZnPc interfaces indicate its applicability as optoelectronic and/or radio/microwave components.Article Citation - WoS: 5Citation - Scopus: 4Thickness and Annealing Effects on the Structural and Optical Conductivity Parameters of Zinc Phthalocyanine Thin Films(inst Materials Physics, 2020) Alharbi, S. R.; Qasrawi, A. F.; Khusayfan, N. M.; Department of Electrical & Electronics EngineeringIn this work, the effects of the thin film thicknesses on the structural, optical absorption, energy band gap, dielectric spectra and optical conductivity parameters of the Zinc phthalocyanine thin films are considered. Thin films of ZnPc of thicknesses of 50-600 nm which are coated onto glass substrates are observed to exhibit amorphous nature of growth. The polycrystalline monoclinic ZnPc phase of the films is obtained via annealing the films at 200 degrees C in a vacuum atmosphere. Increasing the ZnPc films thickness shrunk the energy band gap in the B- and Q- bands and decreased both of the optical conductivities and free holes density in the Q-band. The increase in the film thickness is also observed to decrease the plasmon frequency and the drift mobility of holes in the films. The highest dielectric constant is obtained for films of thicknesses of 100 nm. The annealing process enhanced the optical absorption, redshifts the energy band gap value and the critical energy of the absolute maxima of dielectric constant. In addition, while the heat treatment enhanced both of the scattering times at femtosecond level and the drift mobility, it reduced the free holes density, and the plasmon frequency.Article Citation - WoS: 6Citation - Scopus: 6Dielectric Dispersion at the Mn/Znpc Interfaces(Wiley-v C H verlag Gmbh, 2020) Qasrawi, Atef F.; Zyoud, Hadeel M.Herein, the effects of manganese transparent (150 nm) substrates on the structural, nonlinear optical, and dielectric properties of zinc phthalocyanine are explored. ZnPc thin films are observed to exhibit deformed crystal structure associated with remarkable enhancement in the light absorbability by 21 times at 2.62 eV and by 173 times in the near-infrared (NIR) region of light upon replacement of glass by transparent Mn substrates. The Mn layer also causes a redshift in the energy bandgap, allows generation of free carrier absorption process and increases the dielectric constant by more than 169% in the NIR region. The interaction between the manganese substrates with the organic ZnPc thin layers decreases the free holes density, widens the plasmon frequency range, and improves the drift mobility of holes. The nonlinear dielectric response with the highly improved light absorbability in the NIR range of light nominates the Mn/ZnPc thin films for optoelectronic applications.Article Citation - WoS: 6Citation - Scopus: 6Fabrication of (au, Mn)/Znpc Interfaces as Radiowave/Microwave Band Filters(Wiley-v C H verlag Gmbh, 2020) Qasrawi, Atef Fayez; Zyoud, Hadeel MohammadHerein, zinc phthalocyanine (ZnPc) layers are used as an active material to fabricated radiowave/microwave band filters. The thin layers of ZnPc are coated onto Au and Mn thin-film substrates to form ohmic and Schottky interfaces, respectively. The Au/ZnPc and Mn/ZnPc devices are structurally and electrically characterized by means of X-ray diffraction and impedance spectroscopy techniques in the frequency domain of 0.01-1.80 GHz, respectively. The structural investigations show that both interfaces exhibit strained structures of the monoclinic phase of ZnPc. It is also observed that while the Au/ZnPc/Ag devices display negative capacitance (NC) effects in the microwave region above 1.46 GHz, the Mn/ZnPc/Ag devices show resonance-antiresonance capacitive response in the radiowave region accompanied with NC effects in the range of 0.06-1.80 GHz. In addition, analyses of the reflection coefficient spectra have shown the ability of the (Mn, Au)/ZnPc/Ag interfaces to behave as a typical high-/low-bandpass filters. The filters can be operated in microwaves and radiowave ranges. The return loss spectral investigations on these filters have shown their ability to reach the market standards.
