scholarly journals Effect of pH on the Synthesis of Cobalt Selenide Films by SILAR Method

2021 ◽  
Vol 37 (4) ◽  
pp. 791-796
Author(s):  
Ho Soon Min ◽  
Ng Sha Shiong

The successive ionic layer adsorption and reaction method or called SILAR method was used to produce cobalt selenide thin films for the first time. The deposition was carried out onto the substrate under different various pH values. The X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and ultraviolet visible spectrophotometer were used to investigate the structure, morphology and optical properties of thin films, respectively. The XRD patterns confirmed that the presence of cubic phase cobalt selenide thin films. The grain size increased with increasing the pH value from pH 2 to pH 4 based on the FESEM images. The band gap values are in the range of 2 eV to 2.5 eV.

2015 ◽  
Vol 9 (3) ◽  
pp. 2461-2469
Author(s):  
S. R. Gosavi ◽  
K. B. Chaudhari

CdS thin films were deposited on glass substrates by using successive ionic layer adsorption and reaction (SILAR) method at room temperature. The effect of SILAR growth cycles on structural, morphological, optical and electrical properties of the films has been studied.  The thickness of the deposited film is measured by employing weight difference method. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) studies showed that all the films exhibit polycrystalline nature and are covered well with glass substrates. The values of average crystallite size were found to be 53 nm, 58 nm, 63 nm and 71 nm corresponding to the thin films deposited with 30, 40, 50 and 60 SILAR growth cycles respectively. From the UV–VIS spectra of the deposited thin films, it was seen that both the absorption properties and energy bandgap of the films changes with increasing number of SILAR growth cycles. A decrease of electrical resistivity has been observed with increasing SILAR growth cycle. 


2016 ◽  
Vol 34 (1) ◽  
pp. 204-211 ◽  
Author(s):  
Vishal V. Burungale ◽  
Rupesh S. Devan ◽  
Sachin A. Pawar ◽  
Namdev S. Harale ◽  
Vithoba L. Patil ◽  
...  

AbstractRapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.


2020 ◽  
Vol 20 (10) ◽  
pp. 6235-6244 ◽  
Author(s):  
A. Murugan ◽  
V. Siva ◽  
A. Shameem ◽  
S. Asath Bahadur

The Cu2ZnSnS4 (CZTS) thin films have been prepared at different deposition cycles, deposited on a glass substrate by successive ionic layer adsorption and reaction (SILAR) method followed by the annealing process at elevated temperature. The investigations on the films have been carried out to understand and confirm its structure, functional group present, crystalline morphology, optical and electrochemical behavior. The powder X-ray diffraction patterns recorded indicate that the deposited films are formed in the tetragonal structure. Other parameters like grain size, dislocation density, and microstrain are also calculated. The uniform surface of the films with spherical shaped morphology has been observed by Scanning Electron Microscopy, and the elemental compositions have been confirmed by EDAX. Electrochemical behavior such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge analysis have been carried out by electrochemical workstation. The modified electrode exhibits maximum specific capacitance value as 416 F/g for a pure sample. Optical studies have shown that the band gaps are estimated between 1.40 eV and 1.57 eV.


NANO ◽  
2018 ◽  
Vol 13 (06) ◽  
pp. 1850062 ◽  
Author(s):  
Sh. Khatami ◽  
L. Fekri Aval ◽  
G. Behzadi Pour

In this study Al-doped Zinc Oxide (AZO) thin films were successfully deposited on the flexible Polymethyl methacrylate (PMMA) substrate by RF magnetron sputtering. The effects of RF power on the crystal structure, morphology, thickness and optical properties of AZO thin films have been investigated. The AZO thin films were analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), DEKTAK 3 profilometer, UV–Visible spectroscopy and room temperature photoluminescence (PL) spectroscopy. The XRD patterns show that increase of RF power leads to increase in the predominant direction along (100) and crystal plane of hexagonal ZnO. Moreover, the transmittance of thin films decreased from 76% to 61% and optical bang gap varied among 3.34[Formula: see text]eV to 3.22[Formula: see text]eV with increasing RF power. The PL spectra show excellent light-emitting characteristics: 375[Formula: see text]nm, 428[Formula: see text]nm, 467[Formula: see text]nm and 505[Formula: see text]nm. The results indicate that the peak intensity increases with increasing RF power from 80[Formula: see text]W to 180[Formula: see text]W.


2021 ◽  
Vol 11 (4) ◽  
pp. 7393-7398
Author(s):  
S. M. Ho ◽  
T. J. S. Anand

In this paper, cobalt selenide thin films have been deposited onto glass slides with the SILAR method under various bath temperatures. The structure, optical properties, and morphology of thin films were investigated. The X-ray diffraction patterns confirmed that the number of peak intensities increased with increasing bath temperature. From the AFM images, bigger sizes and thicker films were observed for the films prepared at 80°C. The average grain size was estimated to be 0.2µm, 0.15µm, and 0.25µm when the bath temperature was 40°C, 50°C, and 80°C respectively. The highest absorbance value was observed for films prepared at 80°C. The band gap values range from 2eV to 2.4eV.


2021 ◽  
Vol 8 (12) ◽  
pp. 119-124
Author(s):  
Ho Soonmin

Thin films are attractive materials to be used in laser, solar cells, sensors, phosphors, light emitting diodes, IR windows and flat panel displays. Several deposition methods have been employed to deposit thin films as reported by many researchers. In this report, the cobalt selenide thin films have been deposited onto microscope glass slide via successive ionic layer adsorption and reaction method. This deposition method is a simple method owing to the inexpensive technique and can produce films at a low bath temperature. All the samples were investigated by using XRD, FESEM and UV-visible spectrophotometer. The XRD pattern confirmed that cubic phase cobalt selenide thin films. The FESEM image exhibited that the obtained sample is dense, uniform, and smooth surface. Keywords: XRD, FESEM, Thin films, Cobalt selenide, SILAR technique, Semiconductor, Band gap.


2018 ◽  
Vol 57 (4) ◽  
Author(s):  
Çağlar Duman ◽  
Harun Güney

In this study, zinc oxide (ZnO) thin films are deposited on fluorine doped tin oxide (FTO) substrates by using a successive ionic layer adsorption and reaction (SILAR) method. One of the samples is not annealed and others are annealed at 200, 400 and 600 °C, and all the samples are aged under ultraviolet (UV) light for 19 h. These samples are used to investigate the effect of annealing and aging on the properties of ZnO. Structural properties of the ZnO thin films are examined with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Photoluminescence, transmittance and absorption measurements are used to observe the optical properties of the films. In the literature, there is no study investigating the effect of aging on ZnO thin films deposited with the SILAR method, hence this study fills the gap in the literature.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Deepu Thomas ◽  
Sunil C. Vattappalam ◽  
Sunny Mathew ◽  
Simon Augustine

ZnO thin films were prepared by successive ionic layer adsorption reaction (SILAR) method. The textured grain growth along c-axis in pure ZnO thin films and doped with Sn was studied. The structural analysis of the thin films was done by X-ray diffraction and surface morphology by scanning electron microscopy. Textured grain growth of the samples was measured by comparing the peak intensities. Textured grain growth and photo current in ZnO thin films were found to be enhanced by doping with Sn. ZnO thin film having good crystallinity with preferential (002) orientation is a semiconductor with photonic properties of potential benefit to biophotonics. From energy dispersive X-ray analysis, it is inferred that oxygen vacancy creation is responsible for the enhanced textured grain growth in ZnO thin films.


Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract


Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 106-114
Author(s):  
Yannick Hermans ◽  
Faraz Mehmood ◽  
Kerstin Lakus-Wollny ◽  
Jan P. Hofmann ◽  
Thomas Mayer ◽  
...  

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.


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