scholarly journals Ge-Sb-Te Chalcogenide Thin Films Deposited by Nanosecond, Picosecond, and Femtosecond Laser Ablation

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 676 ◽  
Author(s):  
Georgiana Bulai ◽  
Oana Pompilian ◽  
Silviu Gurlui ◽  
Petr Nemec ◽  
Virginie Nazabal ◽  
...  

Ge-Sb-Te thin films were obtained by ns-, ps-, and fs-pulsed laser deposition (PLD) in various experimental conditions. The thickness of the samples was influenced by the Nd-YAG laser wavelength, fluence, target-to-substrate distance, and deposition time. The topography and chemical analysis results showed that the films deposited by ns-PLD revealed droplets on the surface together with a decreased Te concentration and Sb over-stoichiometry. Thin films with improved surface roughness and chemical compositions close to nominal values were deposited by ps- and fs-PLD. The X-ray diffraction and Raman spectroscopy results showed that the samples obtained with ns pulses were partially crystallized while the lower fluences used in ps- and fs-PLD led to amorphous depositions. The optical parameters of the ns-PLD samples were correlated to their structural properties.

Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.


2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
H. B. Patil ◽  
S. V. Borse

Semiconducting thin films of ternary () have been deposited on glass substrate by the simple and economical chemical bath deposition method. We report the deposition and optimization of the solution growth parameters such as temperature, complexing agent, thiourea, and deposition time that maximizes the thickness of the deposited thin film. The X-ray diffraction deposited thin films having cubic structure. The thin films were uniform and adherent to substrate. The composition was found homogeneous and stoichiometric by EDAX analysis.


Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1454
Author(s):  
Gabriele Barrera ◽  
Federico Scaglione ◽  
Matteo Cialone ◽  
Federica Celegato ◽  
Marco Coïsson ◽  
...  

Bimetallic nanomaterials in the form of thin film constituted by magnetic and noble elements show promising properties in different application fields such as catalysts and magnetic driven applications. In order to tailor the chemical and physical properties of these alloys to meet the applications requirements, it is of great importance scientific interest to study the interplay between properties and morphology, surface properties, microstructure, spatial confinement and magnetic features. In this manuscript, FePd thin films are prepared by electrodeposition which is a versatile and widely used technique. Compositional, morphological, surface and magnetic properties are described as a function of deposition time (i.e., film thickness). Chemical etching in hydrochloric acid was used to enhance the surface roughness and help decoupling crystalline grains with direct consequences on to the magnetic properties. X-ray diffraction, SEM/AFM images, contact angle and magnetic measurements have been carried out with the aim of providing a comprehensive characterisation of the fundamental properties of these bimetallic thin films.


2013 ◽  
Vol 716 ◽  
pp. 325-327
Author(s):  
Xiao Yan Dai ◽  
Cheng Wu Shi ◽  
Yan Ru Zhang ◽  
Min Yao

In this paper, CdTe thin films were deposited on soda-lime glass substrates using CdTe powder as a source by close-spaced sublimation at higher source temperature of 700°C. The influence of the deposition time and the source-substrate distance on the chemical composition, crystal phase, surface morphology and optical band gap of CdTe thin films was systemically investigated by energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscope and the ultraviolet-visible-near infrared absorption spectra, respectively. At the deposition time of 60 min and the source-substrate distance of 5 mm, the CdTe thin films had pyramid appearance with the grain size of 15 μm.


1993 ◽  
Vol 335 ◽  
Author(s):  
Warren C. Hendricks ◽  
Seshu B. Desu ◽  
Chien H. Peng

AbstractTransparent and highly specular PbTiO3 thin films were deposited on sapphire, platinum and ruthenium oxide-coated silicon wafers by hot-wall metallorganic chemical vapor deposition (MOCVD). Lead bis-tetramethylheptadionate and titanium ethoxide were used as chemical precursors. Films were deposited over a range of experimental conditions. X-ray diffraction (XRD) was used to determine the phases present in the films; Scanning Electron Microscopy (SEM) was used to examine the surface morphology and Energy Dispersive Spectroscopy (EDS) was used to determine the composition. Optical spectra were obtained to confirm the highly dense and transparent nature of the films. The chemical stability of the ruthenium oxide substrates in the MOCVD environment as well as the existence of a high-temperature deposition regime for composition control are also discussed.


1996 ◽  
Vol 426 ◽  
Author(s):  
Yuming Zhu ◽  
Dull Mao ◽  
D. L. Williamson ◽  
J. U. Trefny

AbstractChemical-bath-deposited CdS thin films from an ammonia-thiourea solution have been studied by x-ray diffraction, surface profilometry, ellipsometry, and other techniques. The compactness of the CdS films, structural properties of the films, and the growth mechanism have been investigated. For the deposition conditions used, we found that the film compactness reaches its maximum at a deposition time of 35 minutes. Films grown at longer deposition times are less compact, consistent with the CdS duplex layer structure proposed previously. This transition from compact layer growth to porous layer growth is important for depositing CdS films in solar cell applications. Based on x-ray diffraction (XRD) studies, we were able to determine the crystal phase, lattice constant, and other structural properties.


1995 ◽  
Vol 73 (1-2) ◽  
pp. 35-37
Author(s):  
J. Murdoch ◽  
F. S. Razavi ◽  
J. A. Moore

Using magnetron sputtering techniques, several thin films of superconducting BiPbSrCaCuO were fabricated by varying the distance between the substrate (single crystal of MgO with polished (100) plane) and the targets. During the deposition the gas pressure was kept constant at 0.3 mbar (1 mbar = 0.1 kPa) and the substrate temperature was kept at 700 °C. An energy-dispersive X-ray fluorescence was designed using a radioisotope source with a secondary target and a Si(Li) X-ray spectrometer and it was used to measure the atomic composition of the film quantitatively. It was found that the Ca concentration relative to Sr increases linearly as the distance between the substrate and the targets increases. However, both Cu and Bi show a more complex variation of concentration with distance. The X-ray diffraction results also indicated that the films are grown epitaxially along the C axis, which showed a semiconducting behaviour with TC,zero below 60 K.


2017 ◽  
Vol 866 ◽  
pp. 318-321 ◽  
Author(s):  
Nirun Witit-Anun ◽  
Adisorn Buranawong

Titanium aluminum nitride (TiAlN) thin films were deposited by reactive DC magnetron co-sputtering technique on Si substrate. The effect of deposition time on the structure of the TiAlN films was investigated. The crystal structure, surface morphology, thickness and elemental composition were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Al)N solid solution. The as-deposited thin films exhibited a nanostructure with a crystallite size of less than 30 nm. The film thickness increase from 115 nm to 329 nm, while the lattice parameter decrease from 4.206 Å to 4.196 Å, with increasing of the deposition time. Cross section analysis by FE-SEM showed compact columnar and dense morphology as a result of increasing the deposition time. The elemental composition of the as-deposited films varied with the deposition time.


2019 ◽  
Vol 397 ◽  
pp. 81-87 ◽  
Author(s):  
Farid Khediri ◽  
Abdelkader Hafdallah ◽  
Mouna Bouhelal

In this work Zinc oxide thin films prepared by spray pyrolysis technique. A set of ZnO thin films were deposited with various deposition times, on glass substrate at 350 °C. The precursor solution is formed with zinc acetate in distilled methanol with 0.1 molarity. The deposition time was ranged from 2 to 8 min. The structural and optical properties of those films were examined by X-ray diffraction (XRD) and ultraviolet-visible spectrometer (UV). X-ray diffraction patterns of the ZnO thin films showed polycrystalline hexagonal wurtzite structure and the preferred orientation was along (002) plane when the grain size varied between 9.66 and 16.67nm. ZnO thin films were highly transparent in the visible with the maximum transmittance of 85% and the optical band gap was found between 3.25 and 3.28 eV.


Author(s):  
Fatma Salamon

CdS thin films were prepared by chemical bath deposition technique (CBD) onto the glass substrates at different conditions of preparation. The obtained samples are studied by X-Ray diffraction (XRD). The XRD patterns of CdS samples revealed the formation with a hexagonal crystal structure P36mc, and the clear effect of the concentration of thiourea, cadmium sulfide, NaOH, time and temperature deposition, and annealing temperature, on the structure of the prepared thin films. through the study, we found that the samples have preferred orientation along [002], also the thickness of thin films decrease with deposition time after certain value, with the appearance of free cadmium. It has been found that the 200°C is the best temperature for annealing to improve the other structural and physical properties of films.


Sign in / Sign up

Export Citation Format

Share Document