Chemical Bath Deposition Method

A B S T R A C T Herein, ZnMgS nanorod (NR) thin film has been grown by facile single step chemical bath deposition technique. Initially, vertically aligned ZnMgS NR having ∼3 µm length and diameter of ∼200 nm were deposited on commercial glass substrate. The morphology characterizations of this nanorod thin film were observed by FE-SEM and TEM. The randomly oriented hexagonal type nanorods were grown on the glass surface. The strong and highly intense (0 0 2) peak in the XRD pattern along with the calculated low compressive strain indicates vertical growth of high-quality crystalline ZnMgS nanorods. The films showed a direct band transition at ∼3.62 eV. The photosensing properties of NR thin film of ZnMgS showed an excellent photoresponsivity of 34.6 μA/Watt and photosensitivity 99% respectively under illumination of 100 W/cm 2 at a bias voltage 5 V. The obtained experimental results were found to be consistent with theoretical results obtained using DFT.

Thin films of FeCuS were grown on glass substrates by the Chemical Bath Deposition (CBD) technique at room temperature. Iron (III) trioxonitrate nanohydrate, copper chloride dehydrate and thiourea were used as sources for iron, copper and sulphur ions respectively. The optical characterization was done by using a Janway UV- VIS spectrophotometer in the wavelength range of 300 nm – 1100 nm. The optical absorbance of the films was determined directly from the spectrophotometer. Other properties such as transmittance, reflectance refractive index and absorption coefficient squared were calculated. A band gap energy range between 2.5 eV to 2.8 eV was obtained.

In this work thin CdS films using glycine as a complexing agent were fabricated by chemical bath deposition and then doped with silver (Ag), by an ion exchange process with different concentrations of AgNO 3 solutions. The CdS films were immersed in silver solutions using different concentrations during 1 min for doping and after that the films were annealed at 200 • C during 20 min for dopant diffusion after the immersion on the AgNO 3 solutions. The aim of this research was to know the effects of different concentrations of Ag on the optical and structural properties of CdS thin films. The optical band gap of the doped films was determined by transmittance measurements, with the results of transmittance varying between 35% and 70% up to 450 nm in the electromagnetic spectra and the band gap varying between 2.31 and 2.51 eV depending of the silver content. X-ray photoelectron spectroscopy was used to study the influence of silver on the CdS:Ag films, as a function of the AgNO 3 solution concentration. The crystal structure of the thin CdS:Ag films was studied by the X-ray diffraction method and the film surface morphology was studied by atomic force microscopy. Using the ion exchange process, the CdS films' structural, optical and electric characteristics were modified according to silver nitrate concentration used.

Ternary thin films of Iron Copper Sulphide (FeCuS) have been grown and characterized. Optical, compositional, surface microstructure and structural characterization of the deposited films were carried out. Absorbance spectra data of the films were obtained using a Janway 6405 UV-VIS spectrophotometer, absorbance of the films were found to be high in UV and low in VIS – NIR region, while the transmittances were low in UV region and high in VIS – NIR regions. Elemental composition of
the films were done using Skyray XRF Machine, EDX Pocket III, model P530. The machine was used to determine the percentage of each transition element present in the films. The surface microstructures of the films were characterized using Olympus Microscope at 100X magni fication. XRD analysis of the
films was carried out using Enhance Mini Material Analyzer (EMMA) X – Ray Diffractometer Machine, the as - deposited FeCuS thin film was found to have tetragonal structure. The lattice constants obtained are a =10.585 Å, b = 10.585 Å and c = 5.383 Å. The crystallite size of the film was calculated at Cu Kα
wavelength of 1.5406 Å and the calculated grain size was found to be 0.389 nm (3.589 Å).  The optical absorption study reveals that FeCuS thin film has a bandgap of 2.40eV and a refractive index range of 2.00 to 2.70 at 400nm. The reflectance of the deposited films was found to be generally low.

In this work resistance and resistivities of PbS thin films by chemical bath deposition using Polyethylenimine as complexing agent are presented. A series of resistance and resistivity values of thin films obtained at different deposition times of 7, 10 and 13 minutes were evaluated and compared. The obtained films were chemically characterized by X-Ray Photoelectron and Raman spectroscopy confirming the presence of lead and sulfur as PbS. Thickness of the films was measured by ellipsometric spectroscopy; the values were in the range of 80 to 100 nm. Resistivity of the films was measured indirectly using an integrator circuit, the results show that resistivity values vary as a function of the deposition time. PEI films showed a low transmission in the visible range about 2 to 5% and an irregular absorption in the range of 300 to 1050 nm. Roughness of the films was characterized by atomic force microscopy showing values of mean square roughness of 16 nm, presenting different orientation of the clusters and pyramidal shapes.

In present work, we have successfully deposited flower-like CdSe 0.6 Te 0.4 thin films onto glass and FTO coated glass substrates by facile chemical bath deposition (CBD) method. The X-ray diffraction study revealed that the films are polycrystalline in nature exhibiting hexagonal crystal structure. FESEM analysis showed the formation of 3D flowerlike CdSe 0.6 Te 0.4 nanostructures composed of number of flake-like thin nanopetals. Moreover, the optical absorption study revealed the band gap energy of 1.61 eV and water contact angle of CdSe 0.6 Te 0.4 thin film lies in the hydrophilic regime which enhances the intimate contact at electrode/electrolyte interface. The photo-conversion efficiency and fill factor of this photo-electrochemical cell are found to be 0.43% and 0.58, respectively.

The optical properties of Potassium (K) doped zinc oxide (ZnO) thin films deposited onto glass substrate by chemical bath deposition (CBD) technique is investigated. The crystallinity, surface morphology and the element composition of the thin films were studied. The optical behavior of K-doped ZnO thin films were investigated by optical transmittance spectrum and photoluminescence (PL) studies. The energy band gap value determined from the optical transmittance spectrum decreases with the increase in the doping concentration. The optical band gap values of the doped thin films are large due to the small grain sizes. The optical constants such as refractive index, extinction coefficient, real and imaginary parts of dielectric constant as a function of wavelength were determined and our results are consistent with that of alkali doped ZnO thin films. The low extinction coefficient values reveal the good quality of the thin films. The thin films exhibit a high absorption coefficient values. The PL spectra show a UV emission and two weak blue emissions (deep level emissions) for all the films.

Highly sensitive and selective detection of volatile organic compounds (VOCs) with fast response time is imperative based on safety requirements, yet often remains a challenge. Herein, we propose an effective solution, preparing a novel gas sensor comprised of amorphous nanoflake arrays (a-NFAs) with specific surface groups. The sensor was produced via an extremely simple process in which a-NFAs of CdO were deposited directly onto an interdigital electrode immersed in a chemical bath under ambient conditions. Upon exposure to a widely used VOC, diethyl ether (DEE), the sensor exhibits excellent performance, more specifically, the quickest response, lowest detection limit and highest selectivity ever reported for DEE as a target gas. The superior gas-sensing properties of the prepared a-NFAs are found to arise from their open trumpet-shaped morphology, defect-rich amorphous nature, and surface C]O groups.

In this work resistance and resistivities of PbS thin films by chemical bath deposition using Polyethylenimine as complexing agent are presented. A series of resistance and resistivity values of thin films obtained at different deposition times of 7, 10 and 13 minutes were evaluated and compared. The obtained films were chemically characterized by X-Ray Photoelectron and Raman spectroscopy confirming the presence of lead and sulfur as PbS. Thickness of the films was measured by ellipsometric spectroscopy; the values were in the range of 80 to 100 nm. Resistivity of the films was measured indirectly using an integrator circuit, the results show that resistivity values vary as a function of the deposition time. PEI films showed a low transmission in the visible range about 2 to 5% and an irregular absorption in the range of 300 to 1050 nm. Roughness of the films was characterized by atomic force microscopy showing values of mean square roughness of 16 nm, presenting different orientation of the clusters and pyramidal shapes.

Monodispersed FePt alloy magnetic nano-particles are prepared by reduction of platinum acetyl acetonate and iron acetyl acetonate salts together in the presence of oleic acid and oleyl amine stabilizers by polyol process. The particle size of FePt is in the range of 2–3 nm confirmed by transmission electron microscopy (TEM). As-synthesized FePt nano-particles are chemically disordered with face centre cubic (fcc) structure where as after vacuum annealing these particles changed to face centre tetragonal (fct) ordered structure confirmed by the X-ray diffraction technique. Magnetic coercivity of 5.247 KOe was observed for fct structure.

In this work resistance and resistivities of PbS thin films by chemical bath deposition using Polyethylenimine as complexing agent are presented. A series of resistance and resistivity values of thin films obtained at different deposition times of 7, 10 and 13 minutes were evaluated and compared. The obtained films were chemically characterized by X-Ray Photoelectron and Raman spectroscopy confirming the presence of lead and sulfur as PbS. Thickness of the films was measured by ellipsometric spectroscopy; the values were in the range of 80 to 100 nm. Resistivity of the films was measured indirectly using an integrator circuit, the results show that resistivity values vary as a function of the deposition time. PEI films showed a low transmission in the visible range about 2 to 5% and an irregular absorption in the range of 300 to 1050 nm. Roughness of the films was characterized by atomic force microscopy showing values of mean square roughness of 16 nm, presenting different orientation of the clusters and pyramidal shapes.

Thin film of copper sulfide (CuS)  with three molar concentrate of Thiouria (NH2)2CS (TU)  (0.03,0.05 and 0.08) M and Copper Chloride  CuCl2.2H2O  with molar ratio (0.01 )M  have been prepared by Chemical Bath Deposition Technique  on glass substrates at (75οC), for one hour. As deposition and annealed films were studied, the results of X-ray diffraction showed that the films were polycrystalline with Hexagonal structure . The optical properties of CuS thin films recording by the transmittance and absorbance spectrum for wave length  range (300-1100) nm, the results showed that the transmittance increases with increasing molar concentration of Sulfide source (TU) for as deposited and annealed films. It is noticed that the electronic transitions is directly allowed transition and the values of energy gap ranging between ( 1.3 – 2.2) eV corresponding to increasing of molar concentration of Thiouria. The purpose of the research is to study the compositional, optical and electrical properties of the prepared films and study the effect of sulfur exporters, On the structural and optical properties.