Chemical Spray Pyrolysis Technique Research Articles

Fabrication of bare and cobalt-doped ZnFe2O4 thin film as NH3 gas sensor with enhanced response through UV-light illumination

This work reports on the deposition of bare and cobalt-doped ZnFe2O4 thin films by chemical spray pyrolysis technique to study ammonia (NH3) gas sensing properties. Colorless and strongly smelling, ammonia (NH3) is readily soluble in water and yields ammonium (NH) ions. These gases mix in the air atmosphere cause climate change, and severely affect human health. Therefore, the detection of NH3 below the exposure limit can avoid the deterioration of human health and environment. Co-doping had a significant effect on surface roughness, surface morphology, crystallite size, and sensitivity at room temperature. Co0.5Zn0.5Fe2O4 film (ZFCO5) exhibited an outstanding response (S = 19) towards 10 ppm NH3 gas at room temperature. Compared to the bare film, the ZFCO5 sensor has an eleven-fold higher gas-detection response value for 10 ppm NH3. This is ascribed to the blended effects of small crystallite size, high surface roughness, oxygen vacancies, and angular shape morphology linked into tiny rods in the ZFCO5 film. The ZFCO5 sensor showed a significant speedup in response/recovery times (102 s/34 s) and good response (S = 25) to NH3 under the UV-light (365 nm) illumination at room temperature. The built-in ZFCO5 gas sensor shows promise for real-time NH3 below threshold level monitoring.

Selective growth and unveiling semiconductor nanostructured based La,Mo and O elements: Structural, morphological, and optical investigations

La2Mo2O9 ternary compound thin film has been prepared by the chemical spray pyrolysis technique on glass substrates at 460°C. Characterization via X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray, X-ray photoelectron spectrometry (XPS) and spectrophotometry through reflectance and transmittance measurements were performed. X-ray analysis shows that La2Mo2O9 material crystallizes in cubic structure belonging to the P 213 space group with a preferred orientation of the crystallites along (210) direction parallel to the substrate plane. Raman spectroscopy witnesses the presence of bonds like La-O and Mo-O. SEM observation shows that the prepared film exhibits a uniform grain of regular sizes in the range of 70–120 nm and some chains. EDX spectroscopy highlights the presence of La, Mo and O elements with a slight non-stoichiometry reflecting the oxygen deficiency. XPS measurements reveal the well defined states O 1s, Mo 3d5/2, Mo 3d3/2, La 3d5/2 and La 3d3/2 of oxygen, molybdenum and lanthanum elements. Optical measurements show a high transparency in the visible range. These measurements were used to deduce the optical band gap and Urbach energy.

Development of Sub‐Band in Spray‐Deposited Cr‐Substituted Chalcopyrite Thin Films for Advancing Solar Cell Efficiency

Designing effective strategies for mitigating energy crisis highlights a research gap in current solar cell technologies. This study explores the inherent physicochemical properties of thin films composed of copper gallium sulfide telluride (CuGa1−xCrx(S,Te)2) with chromium substitution, prepared through the chemical spray pyrolysis technique. The investigation showcases how the concept of intermediate band structuring contributes to enhancing solar cell efficiency. This enhancement can be attributed to the remarkable mobility (from 1.80 to 5.48 cm2 V−1 s−1) and conductivity (from 1.00 to 6.06 S cm−1) exhibited by pure and 0.1 chromium thin films, respectively. Notably, the Cr‐0.1‐substituted CGST film displays maximum photoresponsivity of 0.624 AW−1, an external quantum efficiency of 145%, and a detectivity of 2.37E10. The fabricated solar cell is subjected to theoretical simulation using solar cell capacitance simulator‐1D software, revealing an upward trend in efficiency from 7.13% to 11.23% with increasing Cr substitution from 0.025 to 0.1. This efficiency improvement can be ascribed to the reduction in bandgap (from 2.40 to 1.72 eV) and the creation of a sub‐band in CGST due to Cr incorporation, as substantiated by UV–vis and NIR spectroscopy. These outcomes suggest that Cr‐0.1‐substituted CGST holds promise as a potential thin film absorber material in solar photovoltaics.

Branched ZnFe2O4 nanorods grown via chemical spray pyrolysis technique for chemiresistive xylene gas sensor

In this work, we used a chemical spray pyrolysis technique to deposit zinc ferrite (ZF) thin films at different substrate temperatures to study xylene (C8H10) gas sensing properties. The focus is on the detection of xylene, a volatile organic compound (VOC) that is harmful to human health. It was found that the concentration of hazardous xylene gas was below the exposure limit. The substrate temperature has a notable impact on the sensor's performance, and ZF exhibits promise for discerning xylene selectively at 200 °C operating temperature. The results indicate that the ZF film deposited at 225 °C (ZF-B) exhibited a significant response (S = 47.4%) to a 50-ppm xylene concentration. Further analysis illustrates that the film substrate temperature deposited at 225 °C can have a unique morphology including thin branched rods, small nanorods with high surface area and roughness. These features contribute to enhanced sensing response by creating more active centers for gas molecule interactions. The stability test over 125 days indicates that the ZF-B film acts effectively as a xylene gas sensor, emphasizing the effectiveness of ZF thin films in detecting xylene in an air environment.

Effect of molar concentration on SnS thin films using chemical spray pyrolysis technique

Effect of molar concentration on SnS thin films using chemical spray pyrolysis technique

Highly Transparent and Stable N-Type Protective Layers for Spray Pyrolyzed CuO Thin Films for Photoelectrochemical Energy Conversion- a Comparative Study

Various inexpensive and highly transparent n-type semiconducting oxides (ZnO, NiO, BaSnO3, Fe2O3, and Al2O3) are tested for their possible application as a protective layer on CuO photocathode. All the above films are synthesized by a highly scalable chemical spray pyrolysis technique. Optimized thin layers show high charge carrier concentration 1011- 1017 /cm3 and excellent electron mobility, improved charge separation capability. All of them show large and stable photocurrent density of CuO thin film photocathode when used as a protective layer. Time-Resolved Photoluminescence (TRPL) is measured to understand the carrier lifetime in them. The photo-electrochemical behavior of all electrodes is performed in the dark and illumination with neutral (pH ~8) and alkaline (pH ~14) electrolytes. Photostability of all prepared heterojunctions ZnO/CuO, NiO/CuO, BaSnO3/CuO, Fe2O3/CuO, and Al2O3/CuO photocathodes are measured under continuous AM 1.5 G illumination for 300 s. Comparative study of solar to chemical conversion efficiency of fabricated photocathodes are presented.

Investigation on visible spectral response of spray coated Ni doped CuGaS2 thin films for photodetector application

The visible light spectrum attracts vast interest in photodetector applications and takes an integral part in image sensing and communication. Ternary chalcopyrite, such as CuGaS2 can be used for visible light detection owing to its higher light absorption coefficient and wider bandgap. This work presents pristine and Nickel-doped CuGaS2 (0.5, 1.0, 1.5 wt. %) thin film photodetectors prepared by the low-cost Chemical Spray Pyrolysis technique. Structural analysis confirms the formation of the pure CuGaS2 phase and the evidence of Ni inclusion inside the lattice. The optical bandgap of the Ni-doped CGS thin films was reduced compared with pristine CuGaS2, leading to higher absorption in the visible region. The interaction of photons with CuGaS2 and its photoconductive mechanism is probed through photoresponse studies. The responsivity and detectivity were calculated for all the photodetectors under constant bias (1V) and power density (4 mW/cm2). All the devices show excellent photoresponse despite having a higher photosensitive area of 1 cm2 and a very low bias for operation. Particularly, 0.5 wt. % Ni-doped CGS photodetector device showed higher responsivity and detectivity of 1.6 μAW−1 and 19.6 × 106 Jones respectively than others. The admirable optical and electrical properties due to Ni doping played a crucial role in this superior performance. Hence, our investigation suggests Ni-doped CuGaS2 thin films can be employed in the fabrication of thin film photodetector devices.

Structural and thermoluminescence properties of magnesium oxide by exposed to beta radiation

In this research, magnesium oxide nanoparticles were produced through the chemical spray pyrolysis technique by using magnesium chloride and deionized water at room temperature. Structural characterization of magnesium oxide was carried out by x-ray diffraction system, the pattern confirmed that the prepared magnesium oxide sample has a pure MgO phase with (2 0 0) orientation. Scanning electron microscopy images (SEM) showed that the surface was covered by spherical and irregular shapes in different sizes on the nanoscale ranging between 50 nm and 100 nm. UV–Vis spectroscopy system was used to estimate the band gap energy; it was equal to 3.7 eV. In addition, we investigated the thermoluminescence and dosimetric characterization of magnesium oxide by studying the TL glow curve intensity. The results exhibited that the intensity of TL is increased with increasing of absorbed dose as a function of the temperature. According to the obtained results, MgO is a promising material as a TLD device.

Effect of ZnS and CdS on Some Physical Properties of MgO Films

This article reports on the fabrication and characterization of MgO nanostructured films and the effect of ZnS and CdS on their structural, optical, and electrical properties. The MgO, MgO: ZnS, and MgO: CdS thin films were deposited using a Chemical spray pyrolysis technique onto glass substrates at 673 K. The XRD patterns revealed that the MgO thin films had a preferred (111) orientation with a pure cubic crystalline structure, while the ZnS and CdS layers had a hexagonal structure. The FE-SEM images showed that the MgO films had a nanostructured morphology with an average particle size of ~50 nm. The UV-Vis spectroscopy results showed that the addition of ZnS and CdS layers to the MgO films resulted in a shift in the absorption edge towards the visible region of the electromagnetic spectrum, indicating an improvement in their optical properties. These findings suggest that the MgOZnS and MgOCdS films could have potential applications in optoelectronic devices.

Properties of Mn3O4 thin film electrodes prepared using spray pyrolysis for supercapacitor application

Film electrodes are made by depositing a thin layer of an electroactive material onto a conductive substrate. The performance of thin film electrodes in energy storage devices is significantly governed by their preparative conditions, particularly the molar concentration of the initial precursor. In the current study, the preparation of Mn3O4 thin film electrodes utilizing the chemical spray pyrolysis technique is discussed. The effect of molar concentration on the structural, morphological, and electrochemical properties of the thin film electrodes was thoroughly investigated using techniques including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) studies. Additionally, X-ray photoelectron spectroscopy (XPS) was employed to gain more insight into the oxidation states of the sample with the best electrochemical performance. Findings suggested that the molar concentration considerably affects the crystallite size, surface area, surface roughness, and wettability, which would directly impact the functionality of the electrode. It was concluded that the electrode deposited using the molar concentration of 0.06 M showed significantly improved performance according to the electrochemical measurements. The areal capacitance of up to 105.3 mF/cm2 in the aqueous electrolyte was recorded from CV measurements at a scan rate of 5 mVs−1. These electrodes could be an option for low-cost, environmentally friendly electrochemical capacitors if prepared under optimal deposition conditions.

Fabrication and Characterization of Sn1-XCuxO2 Thin Films Prepared by Chemical Spray Pyrolysis Technique

Fabrication and Characterization of Sn1-XCuxO2 Thin Films Prepared by Chemical Spray Pyrolysis Technique

Influence of Thickness on Some Physical Characterization for Nanostructured MgO Thin Films

MgO Nanostructured thin films with different thicknesses (200, 400, and 600 nm) have been deposited by the chemical spray pyrolysis technique. The results confirm that the structure, morphology, optical, and electrical properties were all affected by the thickness of the film. MgO films' physical properties were examined using (XRD), (FE-SEM), (EDX), (AFM), (UV-Vis spectrophotometer), and the Hall Effect. According to the structural analysis, the films have a cubic magnesium oxide polycrystalline structure, with a preferred orientation (002). The average Crystalline Size and optical band gap are found in the range (20.79-18.99) nm and (3.439-3.162) eV respectively with an increase in thickness. The surface morphology of the films reveals that they are free of crystal defects such as holes and voids, as well as homogeneous and uniform. The EDS patterns show that the as-grown films contain magnesium and oxygen. The Hall Effect shows that electrical conductivity decreases with thickness. The experimental results show that film thickness influences the physical properties of as-grown MgO thin films and that thicker films can be used as an absorber layer in solar cell applications.

Synthesis and characterization of pure and Cu-doped WO3 thin films for high performance of toxic gas sensing applications

Oxygen vacancies and the high surface area of nanostructured materials offers stronger gas adsorption active sites for improved gas sensing performance. In the present work, we have deposited WO3-based thin films using a chemical spray pyrolysis technique at a substrate temperature of 400 °C with other optimized preparation parameters. Besides, this study reports the influence of Cu doping at various weight percentages on the structural, morphological, optical and toxic gas sensing properties of WO3 films in detail. The crystalline structure of the material was investigated using the X-ray diffraction technique. Each X-ray diffraction analysis of the films demonstrated a polycrystalline nature, matching the hexagonal phase of WO3 with the (200) plane of preferential orientation of crystal growth. The optical characteristics of the thin film's material were analyzed by UV–Vis absorption spectroscopy. The optical energy bandgap (Eg) of the deposited thin films was estimated using the Tauc relation, and the value was decreased along with the increase in the Cu-doping concentration. The surface roughness of the films has been investigated using atomic force microscopy. The TEM patterns of sprayed Cu-doped WO3 thin films exhibit nanocrystalline features. Detecting toxic gasses is of great importance across the globe due to an alarming enhancement in respiratory, ocular, skin, and lung diseases. Hence, cost-effective and room temperature-operated Cu-doped WO3 thin film sensors to trace low concentrations of toxic gasses have been investigated and systematically reported. It is observed that the sensor response is to be increased with the increase in Cu-doping concentration, particularly the 4 wt.% Cu-doped sensor exhibited a response value of 7.2 and fast response and recovery times in the presence of 50 ppm ammonia vapor.

Insights into the replacement of FA by Cs in FAPbI3−xClx thin film fabricated in atmospheric conditions: Inspection of solar cell and photocatalytic performances

Despite remarkable advances of perovskite materials, the stability issue hurdles in the path of commercial deployment of perovskite solar cell and optoelectronics devices. To overcome these, CH3(NH)2PbI3−xClx thin film is deposited by chemical spray pyrolysis (CSP) technique at a temperature of 125 °C under atmospheric conditions and then CH3(NH)2 free Cs based in the form of CsPbI3−xClx is synthesized. The precursor solution shows turbid in nature which became transparent slowly, and after 60 min stirring it became highly transparent that insights crystallization formation for the thin film growth. SEM images exhibit the thin films are pinholes free with grains size (Ave. ∼2 µm) of FAPbI3−xClx are larger enough than that of CsPbI3−xClx. The high crystalline property with pinhole-free surfaces are prerequisite for high performance optoelectronic devices applications. Coexistence mixed phases are observed in XRD patterns could be due to decomposition and/or incomplete reaction of the phases. The thin films exhibit cubic and orthorhombic crystal structures. Grains size and lattice parameters calculations are demonstrated that the films are micro-nanostructures, and their size strongly depends on the films constituents. Band gap can be tuned in between 1.70. eV and 1.62 eV. The solar cell performance was investigated using SCAPS-1D software and the obtained efficiency is to be η = 12.29% of FAPbI3−xClx is coherent with reported results, whereas of CsPbI3−xClx is to be η = 11.15%. From the theoretical photocatalytic calculation, it can be concluded that FAPbI3−xClx may be suitable for O2 production, but CsPbI3−xClx is an efficient candidate for photocatalytic process in the visible region due to nearly equal effectiveness both of the oxidation and reduction processes. Thus, CsPbI3−xClx as a new candidate perovskite for solar cell and photocatalytic applications, requires further attention.

Type conversion as well as bandgap tuning of sprayed SnS thin film and initial trials on heterojunction diodes

Spray-pyrolysed thin films open the door for both economic and eco-friendly portable device production. Moreover, the use of earth-abundant elements such as Sn and Cu for the preparation of thin films will considerably reduce the production cost of the device. Here we are reporting a new technique for bandgap tuning of SnS nanomaterial without adding any type of metal as dopant through a vacuum-free chemical spray pyrolysis technique for various opto-electronic applications such as supercapacitors, batteries, and solar cells. Both p-type and n-type SnS thin films were fabricated. Trial studies were performed on the fabrication of heterojunctions using n-SnS and p-c-Si. The reverse saturation current (J0) value obtained for the diode is 1.7 × 10-6 A. The ideality factor (n) is found to be 2.89. The as-prepared SnS thin films have a bandgap ranging from 1.84 eV to 1.45 eV and a maximum optical absorption coefficient of 105 cm−1 in the wavelength range 400–800 nm.

Study The effect of Annealing and Argon Laser Irradiation on the some optical properties of CuO Thin film

In this research the effect of annealing and Argon Laser Irradiation on some optical properties of CuO thin films have been done. Thin films were prepared by chemical spray pyrolysis technique . The thickness of films was 1000 A°. Optical properties such as Reflectance, Energy band gap and Absorption coefficient as a function of photon energy have been studied within the wavelength range of (300-900) nm, using UV-visible Spectrophotometer, before and after annealing and irradiation. It is found that the optical properties are changed.

Study the Doping Effect of Lead(Pb) on the Optical Properties of Cadmium Sulfide (CdS) Thin Films.

The optical properties of pure and doped Cadmium Sulfide thin films have been stadied in the present work. Cadimum Sulfide can be doped by the Lead of (5%,10%,15%,20%) which prepared by chemical spray pyrolysis technique were deposited on (350ºC) glass substrates. The optical properties– Trasmittance (T), Absorbtance (A), Energy band gap (Eg), Absorption coefficient(α) and Extinction Coefficient (ko) - within wave length range (330-1100)nm. The cadmium sulfide (pure) thin flims were found to exhibit hight trnsmittance abute (82-86)%, the transmittance decreases with the increasing the doped ratio by the lead(Pb).The direct band gap energy of films decreases from (2.40eV) for the pure thin films to (2.35,2.31,2.25,2.19 eV) for the doped by lead at (5%,10%,15%,20%).

DOPING EFFECT BY (Cu , Zn) ON SOME OPTICAL PROPERTIES OF NANOSTRUCTURED (CdS) THIN FILM

In this paper thin films of CdS dopped with Cu and Zn and that mixed with (10, 20%) has been prepared using the Chemical spray pyrolysis Technique deposited on 350ºC glass substrates, The optical properties of these films have been measured in the rang(300-900)nm/wavelength, We Transmittance , Absorpttance, Energy gap , and Absorption coefficient, have been calculated

Thickness Effect on the Electronic Transitions of SnO2 Films

The authors investigated the effect of thickness on the optical properties of thin films of tin dioxide (SnO2) fabricated by the chemical spray pyrolysis technique on glass substrates. Optical measurements were studied in the wavelength ranges 300-900 nm. The optical energy gap decreased from 3.7 to 3.5 eV as the film thickness increases from 250 to 350 nm.

Fabrication of p-type and n-type SnS thin films through vacuum-free deposition techniques

Here, SnS thin films having p and n-type conductivity were fabricated using vacuum-free deposition techniques such as chemical bath deposition (CBD) and chemical spray pyrolysis technique (CSB). The fabricated thin films were subjected to structural, morphological, optical, and electrical analysis using various characterization techniques. The direct optical bandgaps of the SnS-based thin films are 1.80 eV and 1.66 eV. The absorption coefficient of SnS thin films fabricated by the CSP technique is 105 cm−1. The electrical properties of SnS thin films were analyzed by a hall measurement system. The type of conductivity obtained for the SnS thin films was different for both deposition techniques. In the CBD method, p-type conductivity were obtained for SnS films. The SnS thin films fabricated by the CSP technique possess n-type conductivity. The optimum bandgap, high absorption coefficient, type conversion nature and suitable morphology helps the material as potential candidate for thin film based energy generation and energy conversion applications.