Comparison of structural, morphological, linear and nonlinear optical properties of NiO thin films elaborated by Spin-Coating and Spray Pyrolysis

The paper reports on a comparative study of nickel oxide thin films prepared via two different elaboration methods spin-coating and spray pyrolysis. The structure and the surface topography of the NiO thin films have been studied by X-ray diffraction and the atomic force microscope. The optical properties of the deposited films were characterized with the analysis of the experimentally recorded optical transmittance data in the spectral wavelength range of 300–850 nm, via a JENWAY6715 UV–vis spectrophotometer. To complete the comparison, the third order nonlinear optical susceptibility was determined from the third harmonic generation experiment, which in turn were explored by the rotational Maker fringe technique using the beam of Nd:YAG laser at 1064 nm in picoseconds regime. The present work is aimed to exhibit the influence of the elaboration method on the physical properties through analyzing the obtained experimental results

Linear and Nonlinear Optical properties of ZnO Thin Films deposited by Pulsed Laser Depositio

This paper presents the structural and optical properties of ZnO thin films deposited by using pulsed laser deposition technique on quartz substrates. The deposition process was carried out at various temperatures of the substrates from room temperature to 825 K in order to investigate these properties of the films and their mutual influence. The structural and morphological properties of the films were investigated by X-Ray Diffraction and Atomic Force Microscopy measurements, respectively. The quality of the films was improved with an increase of the substrate temperature. The linear optical properties of the films were studied by classic and time-resolved photoluminescence spectra in the broad range of the temperature from 13 K to 325 K. Classic photoluminescence measurement allowed us to estimate band gap energy as a function of the temperature. An innovative time-resolved photoluminescence technique lets us precisely measure the decay time in the real time. Results of these measurements reveal a simple exponential decay behavior typical for well oriented crystalline thin films. Presented spectra confirm high structural and linear optical quality of investigated films. The nonlinear optical properties of the films were investigated by Third Harmonic Generation technique. Our results also indicated that the substrate temperature strongly affected nonlinear optical properties and the values of third order nonlinear susceptibilities were found to be high enough for the potential applications in the optical switching devices

Influence of Bi doping on the electrical and optical properties of ZnO thin films Superlattices and Microstructures

Transparent conducting ZnO doped Bi thin films were prepared on glass substrates by ultrasonic spray method. The influence of Bi doping concentration on the structural, optical and nonlinear optical properties of ZnO thin films was studied. The X-ray diffraction (XRD) analysis show that all studied films have a hexagonal wurtzite structure and are preferentially oriented along the c-axis from substrate surface. Optical transmittance measurements show that all samples have average 80% transparency in the visible light. Optical band gap values range between 3.14 and 3.28 eV. ZnO film with 3 wt% of Bi showed the highest electrical conductivity. In addition, the second and third order nonlinear susceptibilities were determined and their values have been calculated

Experimental and theoretical investigation of molecular structure and charge transfer within some transfer within some 8-hydroxyquinoline derivatives

A serie of novel 8-hydroxyquinoline derivatives: 5-HHQ, 5-MHQ, 5-EHQ and 5-PHQ were synthesized and characterized by means of IR, 1H and 13C NMR spectroscopic analysis. The crystal structures of 5-EHQ and 5-PHQ were solved by X-ray diffraction measurements on single crystal, the two others on powder samples. The UV–Visible spectra of molecules were performed in acetonitrile and ethanol. Density Functional Theory (DFT) and Hartree Fock (HF) methods have been used to determine its optimized geometrical parameters. Theoretical calculations such as HOMO-LUMO energies in fundamental state, in acetonitrile and ethanol, electronic dipole moments and atomic charges distribution were carried out for the title molecules using DFT (B3LYP) method at 6-311G (d, p) set. The results give us some explanation on the molecular structures, the intra charge transfer, relationships between the number of carbons connected to 5-hydroxymethyl-8-hydroxyquinoline and the bioactivity of selected derivatives

Experimental and theoretical investigation of molecular structure and charge transfer within some transfer within some 8-hydroxyquinoline derivatives

International audienceA serie of novel 8-hydroxyquinoline derivatives: 5-HHQ, 5-MHQ, 5-EHQ and 5-PHQ were synthesized and characterized by means of IR, 1H and 13C NMR spectroscopic analysis. The crystal structures of 5-EHQ and 5-PHQ were solved by X-ray diffraction measurements on single crystal, the two others on powder samples. The UV–Visible spectra of molecules were performed in acetonitrile and ethanol. Density Functional Theory (DFT) and Hartree Fock (HF) methods have been used to determine its optimized geometrical parameters. Theoretical calculations such as HOMO-LUMO energies in fundamental state, in acetonitrile and ethanol, electronic dipole moments and atomic charges distribution were carried out for the title molecules using DFT (B3LYP) method at 6-311G (d, p) set. The results give us some explanation on the molecular structures, the intra charge transfer, relationships between the number of carbons connected to 5-hydroxymethyl-8-hydroxyquinoline and the bioactivity of selected derivatives

Study of 5-azidomethyl-8-hydroxyquinoline structure by X-ray diffraction and HF-DFT computational methods

5-Azidomethyl-8-hydroxyquinoline has been synthesized and characterized using IR, 1 H and 13 C NMR spectroscopic methods. Thermal analysis revealed no solid-solid phase transitions. The crystal structure of this compound was refined by Rietveld method from powder X-ray diffraction data at 295 K. The single crystal structure of the compound at 260 K was solved and refined using SHELX 97 program. According to the data obtained by both methods, the structure of the compound is monoclinic, space group P2 1 /c, with Z = 4 and Z ' = 1. For the single crystal at 260 K, a = 12.2879 (9) Å, b = 4.8782 (3) Å, c = 15.7423 (12) Å, β=100.807(14)°. Mechanisms of deformation resulting from intra-and intermolecular interactions, such as hydrogen bonding, induced slight torsions in the crystal structure. The optimized molecular geometry of 5-azidomethyl-8-hydroxyquinoline in the ground state is calculated using density functional theory (B3LYP) and Hartree-Fock (HF) methods with the 6-311G(d,p) basis set. The calculated results show good agreement with experimental values. Energy gap of the molecule was found using HOMO and LUMO calculation which reveals that charge transfer occurs within the molecule

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