• Ahmed Farouk Al-Hossainy

      Articles written in Bulletin of Materials Science

    • Synthesis, spectral, thermal, optical dispersion and dielectric properties of nanocrystalline dimer complex (PEPyr–diCd) thin films as novel organic semiconductor

      Ahmed Farouk Al-Hossainy

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      Dimer complex PEPyr–diCd (5a) has been prepared by reacting CdCl$_2$·2.5H$_2$O with 1,1$'$-bis(diphenylphosphino)ethyl-6-methyl-3-(pyridin-2-yl)-1,4-dihydro-pyridazine tungsten tetracarbonyl PEPyr (4a) as bipyridine ligand. The structural properties of PEPyr–diCd complex were characterized on the basis of elemental analysis (EA), Fourier transform infrared spectra, fast atom bombardment-mass spectrometry, thermogravimetric/ differential thermal analysis, and 1H nuclear magnetic resonance spectroscopy. The crystal is orthorhombic, space group Pbca. Cd(II) metal in PEPyr–diCd organic semiconductor complex coordinated with two N of the PEPyr and three Cl$^−$ (one terminal and two bridging). The micro-structural properties of the films were studied via X-ray diffraction, and scanning electron microscopy. The as-deposited films were annealed in air for 1 h at 150, 200, and 250°C. An average transmittance >70% for PEPyr–diCd complex at higher wavelength >800 nm was observed.In UV spectrum, the transmittance increases followed by a sharp decrease at wavelength 700–750 nm within visible range. The results of the absorption coefficient were determined to find the binding energy (EB) of PEPyr–diCd organic semiconductor complex as 0.242 and 0.47 eV, respectively. Refractive index (𝑛) and absorption index (𝐾) of PEPyr–diCd complex were calculated. Moreover, the dispersion parameters such as dispersion energy, oscillator energy, dielectric constant, and dissipation factor were determined. The oxidation of the imino-phosphine derivatives were examined using cyclic voltammetry in methylene chloride solvent. The cyclic voltammogram of PEPyr–diCd (5a) organic semiconductor appears to have two quasi-reversible oxidations at 543 and 441 mV. The obtained results indicate that the PEPyr–diCd organic semiconductor thin film is a good candidate in optoelectronic devices based on its band gap and dispersion parameters.

    • Eco-friendly method to synthesize and characterize 2D nanostructured (1,2-bis(diphenyl-phosphino)ethyl) tungsten tetracarbonyl methyl red/copper oxide di-layer thin films


      More Details Abstract Fulltext PDF

      Three-layer thicknesses ($T_1 = 50$, $T_2 = 75$ and $T_3 = 100$ nm) of 1,2-bis(diphenylphosphino)ethyl tungsten tetracarbonyl methyl red (DPE-W-MR) were deposited onto the CuO thin film (50 nm) to produce DPE-W-MR/CuOdi-layer thin films by sol–gel spin-coating technique. The composition and the chemical structure of the as-prepared thin films were characterized using various techniques including elemental analysis, Fourier transform infrared spectroscopy,${}^1$H-NMR and X-ray diffraction (XRD). Scanning electron microscopy was used to investigate the size and shape of the CuO nanoparticles and the fabricated thin films. The films are crystalline as evidenced by the XRD pattern and DPE-W-MR has an orthorhombic crystal system. The crystallite size was calculated from an analysis of the line broadening features using theScherrer formula; the average crystallite sizes of DPE-W-MR/CuO di-layer thin films are 52.92, 56.24 and 72.26 nm for $T_1$, $T_2$ and $T_3$, respectively. Thermogravimetric analysis and the thermal curve of DPE-W-MR complex were studied. Optical properties of DPE-W-MR/CuO di-layer thin films are discussed. The optical band gap energies of DPE-W-MR di-layer thin films/CuO decreased (2.25, 2.1 and 1.88 eV) as the film thickness increased (from $T_1$ to $T_3$). Based on the optical results and the quantum confinement effects, the DPE-W-MR/CuO di-layer thin films may be candidates as semiconductor materialsfor optoelectronic devices.

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    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

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      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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