The OIV 1407.3\AA /1401.1\AA\ emission-line ratio in a plasma

Line ratio of O IV 1407.3 \AA/1401.1 \AA\- is calculated using mostly our own atomic and collisional data. Energy levels and oscillator strengths needed for this calculation have been calculated using a Hartree-Fock relativistic (HFR) approach. The electron collision strengths introduced in the statistic equilibrium equations are fitted by polynomials for different energies. Comparison has also been made with available theoretical results. The provided line ratio has been obtained for a set of electron densities from $10^{8}$ cm$^{-3}$ to $10^{13}$ cm$^{-3}$ and for a fixed temperature of 50 000 K.Comment: 6 pages, 1 figure, 2 tables. Accepted for publication in Advances in Space Researc

Expectation Values of the Neutral Chromium Radius

Neutral Chromium (Cr I) is an important element in many laboratory plasma applications. In this work, expectation values of the radius for Cr I are calculated. These atomic data are calculated with three different atomic codes: Cowan code using the Hartree–Fock Relativistic approximation, SUPERSTRUCTURE and AUTOSTRUCTURE codes using scaled Thomas–Fermi–Dirac–Amaldi potential. Relativistic corrections are introduced according to the Breit–Pauli approach. The 3 d 5 4 s , 3 d 4 4 s 2 , 3 d 5 4 d , 3 d 5 4 p and 3 d 4 4 s 4 p configurations are included to obtain the expectation values of radius of Cr I and compared with available data. The novelty of our work is to obtain new values of < 1 r > , < r > , and < r 2 > for the configuration of 4 p and 4 d and the values of < r 3 > for all orbitals configurations considered in this work

Structural, electrical and optical properties of multilayer TiO2 thin films deposited by sol–gel spin coating

Titanium dioxide (TiO2) multilayer thin films having 1, 2, 3 and 4 layers have been deposited on glass substrate by using “sol–gel spin coating” technique. TiO2 has anatase crystal structure and the grain size is increased when the coating layers have been increased, according to XRD results. Four point probe measures the electrical properties showed that the average resistivity is decreased with increasing the stacked layers. “Optical properties” of the films were measured by “UV–Vis spectroscopy” which showed the high transmittance in the visible region. The “optical band gap energies” of 1, 2, 3 and 4 layers of TiO2 films were 3.65, 3.60, 3.59 and 3.40 eV, respectively. These properties showed that the multilayer films of TiO2 can be enhanced the properties of optoelectronic devices. Keywords: Multilayer films, TiO2, XRD, Optoelectronic

Characterizations of multilayer ZnO thin films deposited by sol-gel spin coating technique

In this work, zinc oxide (ZnO) multilayer thin films are deposited on glass substrate using sol-gel spin coating technique and the effect of these multilayer films on optical, electrical and structural properties are investigated. It is observed that these multilayer films have great impact on the properties of ZnO. X-ray Diffraction (XRD) confirms that ZnO has hexagonal wurtzite structure. Scanning Electron Microscopy (SEM) showed the crack-free films which have uniformly distributed grains structures. Both micro and nano particles of ZnO are present on thin films. Four point probe measured the electrical properties showed the decreasing trend between the average resistivity and the number of layers. The optical absorption spectra measured using UV–Vis. showed the average transmittance in the visible region of all films is 80% which is good for solar spectra. The performance of the multilayer as transparent conducting material is better than the single layer of ZnO. This work provides a low cost, environment friendly and well abandoned material for solar cells applications. Keywords: Multilayer films, Semiconductor, ZnO, XRD, SEM, Optoelectronic propertie

Investigations of the structural, morphological and electrical properties of multilayer ZnO/TiO2 thin films, deposited by sol–gel technique

Investigations of the structural, morphological and electrical properties of multilayer ZnO/TiO2 thin films deposited by sol–gel technique on glass substrate. Sol–gel is a technique in which compound is dissolved in a liquid in order to bring it back as a solid in a controlled manner. TiO2 solution was obtained by dissolving 0.4 g of TiO2 nano powder in 5 ml ethanol and 5 ml diethylene glycol. ZnO solution was obtained by dissolving 0.88 g zinc acetate in 20 ml of 2-methoxyethanol. X-ray diffraction (XRD) (PW 3050/60 PANalytical X’Pert PRO diffractometer) results showed that the crystallinity is improved when the number of ZnO/TiO2 layers increased. Also it shows the three phases (rutile, anatase and brookite) of TiO2. Surface morphology measured by scanning electron microscopy (SEM) (Quanta 250 fei) revealed that Crakes are present on the surface of ZnO/TiO2 thin films which are decreased when the number of ZnO/TiO2 layers increased. Four point probe (KIETHLEY instrument) technique used to investigate the electrical properties of ZnO/TiO2 showed the average resistivity decreased by increasing the number of ZnO/TiO2 layers. These results indicated that the multilayer thin films improved the quality of film crystallinity and electrical properties as compared to single layer. Keywords: Semiconductors, Sol–gel, XRD, SEM, Four point prob