Spray deposition process of polycrystalline thin films of CuWO4 and study on its photovoltaic electrochemical properties

2005 ◽  
Vol 59 (24-25) ◽  
pp. 3149-3155 ◽  
Author(s):  
Prashant K. Pandey ◽  
N.S. Bhave ◽  
R.B. Kharat
1987 ◽  
Vol 01 (02) ◽  
pp. 579-582
Author(s):  
Guang-yao Meng ◽  
Xian-dong Wang ◽  
Xue-jun Chen ◽  
Pei-zhen Fu ◽  
Pinghua Yang ◽  
...  

A Chemical spray deposition process with mixed nitrate solution as source was developed to prepare thin films of Ba-Y-Cu oxide on sapphire substrate. By adjusting the source composition and deposition conditions, we have successfully obtained the films in thickness of 2–15μm with essentially orthorhombic Ba2YCu3O7 phase. The films behave super conducting transition with onset above 90K and zero resistance at 68.4K to date. It is believed that the tails in the resistance transition can be improved by searching proper heat treatment and using suitable substrates such as ZrO2 and SrTiO3.


1999 ◽  
Vol 562 ◽  
Author(s):  
Adriana E. Lita ◽  
John E. Sanchez

ABSTRACTThe evolution of crystallographic texture, grain size and surface morphology in magnetron sputter deposited Al-0.5wt.% Cu polycrystalline thin films is reported as a function of film thickness for SiO2 and SiO2/Ti underlayers for several deposition rates. Regardless of the underlayer type, the initial ≈ 10 nm of the Al-Cu films is nearly randomly oriented, with the films developing a (111) out-of-plane texture which increases in strength with thickness during deposition. The AlCu films on sputtered Ti underlayers developed an exact (111) fiber orientation while Al-Cu films on oxide substrates were offset ≈ 5° from exact fiber orientation. Higher deposition rates were found to result in slightly better (111) textured 20 nm AlCu films. The surface morphology of films, determined by Atomic Force Microscopy (AFM), revealed two regimes of average roughness (Rrms) evolution during deposition. Rrms decreased early in the deposition process, followed by a roughening regime where Rrms increased with thickness. These results are discussed in terms of mechanisms such as grain growth, which help to determine microstructure development during film formation from the vapor.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1964
Author(s):  
Julian Kund ◽  
Sven Daboss ◽  
Tommaso Marchesi D’Alvise ◽  
Sean Harvey ◽  
Christopher V. Synatschke ◽  
...  

Polydopamine (PDA) is a synthetic eumelanin polymer which is, to date, mostly obtained by dip coating processes. In this contribution, we evaluate the physical and electrochemical properties of electrochemically deposited PDA films obtained by cyclic voltammetry or pulsed deposition. The obtained PDA thin films are investigated with respect to their electrochemical properties, i.e., electron transfer (ET) kinetics and charge transfer resistance using scanning electrochemical microscopy and electrochemical impedance spectroscopy, and their nanomechanical properties, i.e., Young’s modulus and adhesion forces at varying experimental conditions, such as applied potential or pH value of the medium using atomic force microscopy. In particular, the ET behavior at different pH values has not to date been investigated in detail for electrodeposited PDA thin films, which is of particular interest for a multitude of applications. Adhesion forces strongly depend on applied potential and surrounding pH value. Moreover, force spectroscopic measurements reveal a significantly higher percentage of polymeric character compared to films obtained by dip coating. Additionally, distinct differences between the two depositions methods are observed, which indicate that the pulse deposition process leads to denser, more cross-linked films.


2013 ◽  
Vol 32 (1) ◽  
pp. 309 ◽  
Author(s):  
Srdjan P Petrović

The influence of annealing temperature on the morphology and surface fractal dimension of titanium dioxide (TiO2) films prepared via the spray deposition process was investigated. Thin films with various morphologies were obtained at different temperatures and characterized by X-ray diffraction and atomic force microscopy (AFM). It was found that the crystalline structure of TiO2 films depends strongly on annealing temperature. At higher temperatures, the partial phase transformation of anatase-to-rutile was observed. The morphology and surface fractal dimensions were evaluated by image analysis methods based on AFM micrographs. The results indicate that the value of surface roughness (the standard deviation of the height values within the given area of AFM image) of TiO2 films increases with increasing annealing temperature. Fractal analysis revealed that the value of the fractal dimension of the samples decreases slowly from 2.23 to 2.15 following the annealing process.  


2017 ◽  
Vol 22 (4) ◽  
pp. 1197-1207 ◽  
Author(s):  
T. Rajesh Kumar ◽  
P. Prabukanthan ◽  
G. Harichandran ◽  
J. Theerthagiri ◽  
Tetiana Tatarchuk ◽  
...  

Author(s):  
D J H Cockayne ◽  
D R McKenzie

The study of amorphous and polycrystalline materials by obtaining radial density functions G(r) from X-ray or neutron diffraction patterns is a well-developed technique. We have developed a method for carrying out the same technique using electron diffraction in a standard TEM. It has the advantage that studies can be made of thin films, and on regions of specimen too small for X-ray and neutron studies. As well, it can be used to obtain nearest neighbour distances and coordination numbers from the same region of specimen from which HREM, EDS and EELS data is obtained.The reduction of the scattered intensity I(s) (s = 2sinθ/λ ) to the radial density function, G(r), assumes single and elastic scattering. For good resolution in r, data must be collected to high s. Previous work in this field includes pioneering experiments by Grigson and by Graczyk and Moss. In our work, the electron diffraction pattern from an amorphous or polycrystalline thin film is scanned across the entrance aperture to a PEELS fitted to a conventional TEM, using a ramp applied to the post specimen scan coils. The elastically scattered intensity I(s) is obtained by selecting the elastically scattered electrons with the PEELS, and collecting directly into the MCA. Figure 1 shows examples of I(s) collected from two thin ZrN films, one polycrystalline and one amorphous, prepared by evaporation while under nitrogen ion bombardment.


Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.


Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.


1997 ◽  
Vol 296 (1-2) ◽  
pp. 114-117 ◽  
Author(s):  
O. Pesty ◽  
P. Canet ◽  
F. Lalande ◽  
H. Carchano ◽  
D. Lollman

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