3 results
Search Results
Now showing 1 - 3 of 3
Article Citation - WoS: 8Citation - Scopus: 8Effect of Lithium Nanosandwiching on the Structural, Optical and Dielectric Performance of Moo3(Elsevier, 2019) Al Garni, S. E.; Qasrawi, A. F.In this article, we discuss the effects of lithium nanosheets on the structural, optical, dielectric and optical conductivity parameters of the MoO3 films. The nanosandwiching of Li layers between two layers of MoO3 of thicknesses larger than 20 nm induced the crystallization process of the amorphous MoO3. Namely, MoO3 thin films that are nanosandwiched with Li sheets of thicknesses larger than 50 nm, exhibit structural phase transitions from hexagonal to monoclinic and reveals larger crystallite sizes. The possible formation of Li2O at the MoO3/Li/MoO3 interfaces is simulated and discussed. Optically, the Li nanosandwiching is observed to enhance the light absorbability by 11.0 times at 2.0 eV and successfully engineered the energy bands gap in the range of 3.05-0.45 eV. It also enhances the dielectric performance. In addition, relatively thick layers of lithium (200 nm) succeeds in converting the conductivity type from n-to p-type. The modeling of the dielectric spectra in accordance with the Drude- Lorentz approach have shown that the presence of Li in the structure of MoO(3 )significantly increases the drift mobility values of electrons from 5.86 to 11.40 cm(2)/V. The plasmon frequency range for this system varies in the frequency domain of 0.32-5.94 GHz. The features of MoO3/Li/MoO3 interfaces make them attractive for thin film transistor technology as optical receivers being promising for use in optical communications.Article Citation - WoS: 1Citation - Scopus: 1Structural, Optical and Dielectric Performance of Molybdenum Trioxide Thin Films Sandwiched With Indium Sheets(inst Materials Physics, 2020) Abusaa, M.; Qasrawi, A. F.; Kmail, H. K.; Khanfar, H. K.; Department of Electrical & Electronics EngineeringIn this work, we report the enhancements in the structural, optical and dielectric properties of molybdenum trioxide that are achieved by insertion of 50 and 100 nm thick indium sheets between layers of MoO3. The films which are coated onto ultrasonically glass substrates under a vacuum pressure of 10 -5 mbar exhibited metal induced crystallization process upon insertion of indium sheets. Optically, indium sheets tuned the transmittance and reflectance, significantly, increased the absorption coefficient values and formed interbands in the band gap of MoO3. The energy band gap decreased with increasing indium sheets thickness. On the other hand, the insertion of indium layers into the structure of MoO3 is observed to improve the dielectric response of these films to values that nominate them for used in thin film transistor technology. In the same context, the analyses of the optical conductivity which are carried out with the help of Drude-Lorentz approach have shown that the presence of indium sheets can increase the optical conductivity and enhance the plasmon frequency and free charge carrier density of MoO3. The plasmon frequency is tuned in the range of 1.68-7.16 GHz making MoO3 films attractive for plasmonic applications.Article Citation - WoS: 21Citation - Scopus: 21Design and Characterization of Moo3 Heterojunctions(Elsevier Science Bv, 2019) Al Garni, S. E.; Qasrawi, A. F.In this work, the morphological, compositional, structural, optical and dielectric properties of CdSe which are deposited onto glass and onto MoO3 thin film substrates are investigated. The use of MoO3 as substrate for the growth of CdSe is observed to increase the lattice parameters of the hexagonal unit cell of CdSe and decreases the values of grain size and strain. It also forms band tails of width of 0.20 eV in the band gap of CdSe. The optical analysis has shown that the MoO3/CdSe interfacing results in blue shift in the energy band gap of CdSe and also result in large conduction and valence band of sets of values of 2.12 and 0.94 eV, respectively. The dielectric spectral analysis with the help of Prude-Lorentz approaches for optical conduction, revealed an enhancement in the drift mobility of charge carriers from 15.69 to 39.30 cm(2)/V as a response to the incident electromagnetic field. The free carrier density of the MoO3/CdSe being of the order of 10(17) cm(-3) with the large valence and conduction band offsets and the sufficiently large drift mobility nominates the MoO3/CdSe heterojunctions as an effective component of optoelectronic technology including thin film transistors.
