2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 9Citation - Scopus: 9Indium Slabs Induced Structural Phase Transitions and Their Effects on the Electrical and Optical Properties of Stacked Layers of the Thermally Annealed Cu2o Thin Films(Elsevier, 2020) AlGarni, Sabah E.; Qasrawi, A. F.In this work, the effects of the structural evolutions caused by the insertion of indium slabs (100 nm) between layers of cupric oxide on the electrical and optical properties are investigated. The stacked layers of Cu2O/Cu2O (CC) which are thermally annealed at 500 degrees C in a vacuum media is observed to comprise both of the CuO (45.9%) and Cu2O (54.1%) phases in its structure. The major structural phase of CuO and Cu2O are monoclinic and orthorhombic, respectively. Insertion of indium slabs which is followed by thermal annealing reduced the content of CuO to 29.2% and enriched the content of Cu2O to 70.8%. The CC samples exhibited structural phase transitions from monoclinic CuO to hexagonal Cu2O in the presence of indium and under thermal annealing. The insertion of indium slabs in the samples increased the crystallite size and enhanced the optical transmittance. It also decreased the microstrain, the defect density and the electrical resistivity. The donor states are shifted deeper below the conduction band edge. The nature of optical transitions also changed from direct allowed to direct forbidden with a decrease in the energy band gap values from 2.05 to 0.85 eV upon indium slabs insertion followed by annealing process.Article Citation - WoS: 10Citation - Scopus: 10Effects of Indium Slabs on the Structural and Electrical Properties of Stacked Layers of Cu2o(Natl inst R&d Materials Physics, 2020) Qasrawi, A. F.; Omar, A.; Department of Electrical & Electronics EngineeringIn this work, the structural and electrical properties of stacked layers of Cu2O that comprises indium slabs in its structure are reported. The stacked layers which are coated onto glass and Au substrates under vacuum pressure of 10(-5) mbar are characterized by the X-ray diffraction and impedance spectrometry techniques. While the Cu2O/Cu2O (CC) layers exhibited amorphous nature of growth, those which contained indium slabs (CIC) displayed weak crystallinity The insertion of indium slabs between stacked layers of cuprous oxide highly increased the electrical resistivity and shifted the acceptor level closer to the valance band edge. In addition, the analyses of the conductance and capacitance spectra in the frequency domain of 0.01-1.0 GHz have shown that these two physical parameters are strongly affected by the insertion of indium slabs and by surface deformation effects. The capacitance spectra showed negative capacitance effect (NC) in all the studied frequency domain The NC effects become less pronounced in the CIC samples owing to the changes in the polarization mechanism. The feature of NC effects make both of the CC and CIC samples more appropriate for electronic and telecommunication technology as it can be used in amplifiers to enhance he gain, as parasitic cancellers and as noise reducers.
