Spray Pyrolysis Route Research Articles

PHOTOTHERMAL DEFLECTION ANALYSIS OF β-In2S3 THIN FILMS: THE EFFECT OF S/In MOLAR RATIOS

[Formula: see text]-In2S3 thin films ([Formula: see text], 2 and 4) were prepared using the pneumatic spray pyrolysis (PSP) route to analyze the effect of the S/In ratio on the physical properties. These properties were conducted using the photothermal deflection spectroscopy (PDS) method. The PDS signal amplitudes as a function of wavelength show multiple reflections which appear for all prepared In2S3 films. Such multiple reflections indicate homogeneity and high crystalline quality of the films. The deduced values of the optical band gap vary in the range 2.55–2.65[Formula: see text]eV. The highest thermal diffusivity is obtained for [Formula: see text]. The product ([Formula: see text]) is found in order of 10[Formula: see text][Formula: see text]cm[Formula: see text]/V. The estimated carrier diffusion lengths are 0.06, 0.11 and 0.09[Formula: see text][Formula: see text]m for films corresponding to [Formula: see text], 2 and 4, respectively. Defect absorption in [Formula: see text]-In2S3 films is also investigated by PDS. Five absorption peaks are observed. These absorption peaks contain defect information in the band gap. Hence, this work evidences that [Formula: see text]-In2S3 is a multi-functional material that can be used in optoelectronic, photovoltaic and visible-irradiation photocatalyst applications.

Insights into the consequence of (Al–Zn) dual-doping on structural, morphological, and optoelectrical properties of CdO thin films

The present study explores the structural, morphological, optical, and electrical properties of spray pyrolyzed (Al–Zn) dual-doped CdO thin films. The un-doped and (Al–Zn) dual-doped CdO thin films have been deposited on glass substrate using spray pyrolysis route at 325 °C. The physical properties of the doped samples were analyzed as a function of Zn concentration (2–5 mol%) with constant Al (3 mol%) concentration. XRD analysis confirms the successful incorporation of (Al–Zn) dual-doping into CdO crystal as well as the polycrystalline nature was evident. No phase transitions were apparent from XRD data while revealing the single cubic structure of all the samples. The surface morphology of the samples studied by SEM. It shows the formation of rock-shaped microstructure and the variation of grain size with doping concentrations. Optical analysis was done using UV–vis spectroscopy within the range of 300–1200 nm. Maximum value of transmittance was attained for 3% (Zn–Al)-doped CdO sample. The dual doping exhibits the broadening of band gap values (2.61–3.84 eV) whereas a decrease in extinction coefficient was noticed as a function of Zn doping concentration. Electrical analysis was done using the four-probe method and a high resistivity was seen for higher Zn concentration. Obtained results and precise comparison with some similar films suggested that 2% Zn and 3% Al co-doping can be a suitable candidate for optoelectronic devices.

The effect investigates of temperature on the optical and electrical properties of sprayed SnS: experimental and theoretical study

In this study, Tin monosulfide SnS semiconductor absorbers was deposited by chemical spray pyrolysis route on the glass substrate. We examined the impact of substrate temperature on the structural, morphological, linear optical and electrical characteristics of SnS absorber at many substrate temperatures such as 50 °C, 375 °C and 400 °C. The SnS films have been analysed by diverse techniques like X-ray diffraction, Raman spectroscopy, Scanning electron microscopy and UV-Vis spectrophotometer. The X-ray diffraction (XRD) spectra revealed that the SnS crystallize in the orthorhombic crystal system with the apparition of the preferential crystallographic direction oriented along (111) planes. The SEM micrographs indicate a great uniformity and granular morphological surface of SnS films. Linear optical constants such as energy gap (Eg), coefficient of extinction (k), index of refraction (n), optical conductivity (σopt), as well as the electrical properties confirm the suitable application of SnS thin films as absorber layer in the optoelectronic device applications. Additionally, we have applied the density functional theory DFT and GGA generalized gradient approximation to study the electronic characteristics; as a result of the electronic band structure the SnS absorber has a suitable energy gap.

Facile fabrication of thermochromic VO2 (M) films on TiO2-buffered soda–lime glass via a one-step photo-assisted spray pyrolysis route

VO2(M) films have been considered as promising thermochromic coatings for application in smart windows. Meanwhile, the comprehensive performance of the films required for practical smart windows and their large-scale preparation are still great challenges. In this study, a one-step ultraviolet (UV) photo-assisted spray pyrolysis route was developed to prepare thermochromic VO2(M) films on TiO2-buffered soda–lime glass substrates based on molecular dynamicsimulations and related experiments. According to the results, both the luminous transmittance and solar modulation efficiency of the film deposited at 450 °C and exposed to UV photo-irradiation increased by 17% and 40%, respectively, as compared to those of the non-irradiated films. In the case of VO2 and TiO2 single layers as well as bilayer VO2/TiO2 films deposited on substrates preheated to 350 °C-550 °C, it was found that UV irradiation could promote crystallization along with regulating the phase structure, orientation, and morphology, which enhanced thermochromic performance of the photo-treated films. Therefore, photo-assisted spray pyrolysis deposition is a facile, cost-effective and scalable technology for improving the comprehensive performance of as-obtained materials, which is appealing in the large-scale preparation of VO2 smart windows.

Pressureless sintering of W[sbnd]Ni nanoparticles prepared by ultrasonic spray pyrolysis and hydrogen reduction

The synthesis of homogenous powder mixtures and the characteristic of the sintered W-0.4 wt% Ni compacts were investigated. Ultrasonic spray pyrolysis and polymeric additive solution route for developing the initial powder mixtures were compared based on the resulting microstructure and mechanical property of sintered WNi. The powder mixture synthesized by the ultrasonic spray pyrolysis and hydrogen reduction showed marked refinement of W particle size and homogeneous dispersion of the Ni activator in the form of nickel hydroxide. The WNi powder from ultrasonic spray pyrolysis, pressureless-sintered at 1400 °C, exhibited the increased relative density of 97.6% and hardness of 4.02 GPa compared with the powder from polymeric additive solution. XPS analysis revealed that Ni, existed as nickel hydroxide state in the powder mixture, was partially dissolved in W during sintering to form an alloy. The increase in relative density was explained by the uniform WNi nanocomposite powder synthesized by ultrasonic spray pyrolysis. The high hardness was mainly due to the refinement of W grains.

Characterization of niobium pentoxide synthesized by spray pyrolysis technique and comparison with hydrothermal method

AbstractNiobium pentoxide (Nb2O5) is a polymorphic ceramic with semiconductor characteristics applied in various fields of study. In this work, the Nb2O5 synthesis by the spray pyrolysis route was compared to the hydrothermal technique. The obtained materials were characterized by N2 physisorption (BET‐N2), average particle size distribution by dynamic light scattering (DLS), X‐ray diffractometry (XRD), transmission electron microscopy (TEM), and X‐ray fluorescence (XRF) spectroscopy. The material synthesized by the spray pyrolysis technique presented high specific area and pore volume, high crystallinity, homogeneity, and nanometric particles, thus representing a potential technique for the Nb2O5 synthesis.

Scrutinizing the effect of substrate temperature and enhancing the multifunctional attributes of spray deposited copper gallium sulfide (CuGaS2) thin films

ABSTRACT Polycrystalline chalcopyrite CuGaS2 thin films were prepared using a spray pyrolysis route has been considered a potential material for the solar cell absorber layer. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) studied the impact of substrate temperature in the range of 200–300˚C on surface profile and roughness. Powder X-ray diffraction disclosed that the films were polycrystalline at all examined substrate temperatures, with crystallite size increasing with increased substrate temperature. The UV-Vis displays the cut-off wavelength in 550–880 nm for varied substrate temperatures of CuGaS2 thin films, and the observed band gap is 2.75 eV–1.89 eV. The electrical attributes showed the enhancement in mobility (4.632 cm2 V−1 s−1) for varied substrate temperatures of CuGaS2 thin films. The 300˚C temperature sprayed CuGaS2 polycrystalline films are a decent candidate to be apposite as an absorber layer in thin film photovoltaic solar cells.

Mesoporous silica particles by aerosol spray synthesis; solid core and porous shell structure study

Mesoporous silica core shell particles are materials of high interest especially due to pharmaceutical and catalytic applications. In the current work we presented the synthesis of uniformly porous and solid core porous particles by aerosol spray pyrolysis route according to the principles of EISA, by a one step process. The particles are evaluated morphologically by TEM and by nitrogen adsorption and desorption isotherms for pore size distribution and pore connectivity, validating the effect of synthesis parameters on the core size, surface area and porosity of the uniformly porous and core-shell structures. Three different surfactants Brij-58, CTAB, P123 at various concentrations and combinations as well as three different core type compositions of NaCl, CeO2 and, Ce0.8Zr0.2O2 have been evaluated for the controlled synthesis of silica core-shell particles by a scalable synthesis method.

Effect of temperature and improving the optoelectrical attributes of copper gallium sulfide (CuGaS2) thin films

ABSTRACT This work is focused on the optimization and characterization of copper gallium sulfide (CuGaS2) thin film prepared via the spray pyrolysis route. Chalcogenides are compounds having a chalcogen anion and an electropositive element, and these thin films have more absorption coefficients. The structural, optical, electrical, and morphological properties of CuGaS2 thin films are studied using X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-Vis-NIR Spectroscopy, and Hall effect techniques. The above characteristics are studied for both as prepared and annealed Copper Gallium Sulfide (CGS) thin films. These films have a chalcopyrite tetragonal crystal structure. It is a promising material for solar cell applications due to its suitable bandgap and good electrical stability. The results of this study provide a framework for fabricating an optimized CGS absorber layer in photovoltaic solar cells.

Nanoscale chemical and structural investigation of solid solution polyelemental transition metal oxide nanoparticles

Although it has been shown that configurational entropy can improve the structural stability in transition metal oxides (TMOs), little is known about the oxidation state of transition metals under random mixing of alloys. Such information is essential in understanding the chemical reactivity and properties of TMOs stabilized by configurational entropy. Herein, utilizing electron energy loss spectroscopy (EELS) technique in an aberration-corrected scanning transmission electron microscope (STEM), we systematically studied the oxidation state of binary (Mn,Fe)3O4, ternary (Mn, Fe, Ni)3O4, and quinary (Mn, Fe, Ni, Cu, Zn)3O4 solid solution polyelemental transition metal oxides (SSP-TMOs) nanoparticles. Our findings show that the random mixing of multiple elements in the form of solid solution phase not only promotes the entropy stabilization but also results in stable oxidation state in transition metals spanning from binary to quinary transition metal oxide nanoparticles.

Hierarchically structured sub-bands in chalcopyrite thin-film solar cell devices

The study utilizes the inherent physiochemical properties of vanadium-incorporated copper gallium sulfide telluride (CuGa1−xVx(S,Te)2) thin films deposited via a chemical spray pyrolysis route and evokes how the art of intermediate band structuring favours the solar cell efficiency.

Synthesis, performance evaluation, and economic assessment of tailored Pt/TiO2 catalysts for selective biomass vapour upgrading via a scalable flame spray pyrolysis route

Flame-spray pyrolysis offers a scalable approach to the synthesis of tailored nanostructured catalysts for biomass conversion.

One-Step Aerosol Synthesis of SiO2-Coated FeNi Particles by Using Swirler Connector-Assisted Spray Pyrolysis

Silica-coated soft magnetic particles are essential for some powder magnetic cores consisting of primary (coarse particles) and secondary (fine particles) soft magnetic particles in the advancement of electric devices. Herein, we report the first investigation on the direct synthesis of submicron-sized silica-coated FeNi (FeNi@SiO2) particles as the secondary particle using a connector-assisted spray pyrolysis route. Provided by computational fluid dynamics calculation in applying different connector types, i.e., T-shaped and swirler, we found that the mixing performance between FeNi and HMDSO vapor in the swirler connector played an important role in resulting heterogeneous nucleation, which is crucial for obtaining the higher coating ratio (CR) and fewer undesired nanoparticles than that of the T-shaped connector. The as-prepared submicron-sized FeNi@SiO2 particles (353 nm) with the highest CR (95.9%) demonstrated a remarkable DC bias characteristic (Isat) and eddy current loss values on a powder magnetic core, promising the practical application in manufacturing soft magnetic components.

Improvement in photo-device properties of CuO thin films for opto-electronic applications: effects of (Ni, Co) co-doping

We report co-doping effects of transition metal elements (Ni, Co) primarily on the opto-electronic properties of CuO thin films. CuO, CuO:Ni(1%), CuO:Co(1%) and CuO:Ni(1%):Co(1%) thin films were deposited via the spray pyrolysis route. Structural studies revealed the monoclinic CuO structure for all films. For all the films scanning electron microscope (SEM) images showed a crack-free and homogeneous surface. Photoluminescence (PL) spectra of all the films exhibited four emission peaks at 415, 451, 477, and 521 nm wavelengths. The optical bandgap (E g) values were around 2.12 eV, 2.18 eV, 2.05 eV and 1.84 eV for CuO, CuO:Ni(1%), CuO:Co(1%) and CuO:Ni(1%):Co(1%)thin films, respectively. CuO:Ni(1%):Co(1%) photo-device displayed a large responsivity (R) of 0.43 AW−1, external quantum efficiency (EQE) of 100% and detectivity (D *) of 9.55 × 109 Jones. Hence, co-doping of transition metal elements would be one of the effective approaches for enhancing opto-electronic properties of metal oxide compounds.

Significant enhancement in photosensitivity, responsivity, detectivity and quantum efficiency of Co3O4 nanostructured thin film-based photodetectors through Mo doping developed by spray pyrolysis method

Herein, we have developed the high-performance photodetector diodes (p-Co3O4/n-Si and p-Mo@Co3O4/n-Si) by spray pyrolysis route for modern optoelectronic devices. The impact of different molybdenum (Mo) ions concentrations (0, 2, 4, and 6 wt.%) on the structural, morphological, optical and photo-electrical properties of Co3O4 films has been investigated. The X-ray diffraction study confirms the cubic phase of Mo-doped Co3O4 thin films with good crystallinity. From FESEM images, the unevenly sized sphere-like grains were clearly observed which are agglomerated at higher doping levels. UV-VIS spectra confirmed that the thin film owns good absorption and the energy gap varied with Mo doping. The p-Co3O4/n-Si and p-Mo@Co3O4/n-Si (Mo = 2, 4, and 6 wt.%) photodiodes were fabricated. The barrier height of the fabricated diodes was varied in the range of 0.65 to 0.98 eV. The maximum sensitivity of 10382% at 1.2 V has been achieved for 6 wt.% of Mo-doped diodes due to the creation of photo-created charge couples. Also, the quantum efficiency of the diode was enhanced from 39 to 164%. The 6 wt.% of p-Mo@Co3O4/n-Si junction diode exhibited the highest device performance among others and can be used as high performance photodetector.

Structural, optical, and electrical properties of NixZn1−xFe2O4 thin film prepared by spray pyrolysis route

Structural, optical, and electrical properties of NixZn1−xFe2O4 thin film prepared by spray pyrolysis route

Enhanced multifunctional attributes of Tellurium incorporated CuGaS2 thin films employing spray pyrolysis route

CuGaS2 (CGS) chalcopyrite semiconductor is a promising candidate for thin-film based photovoltaic devices due to its exceptional optical absorption coefficient and flexibility in tuning the optical bandgap. Unfortunately, though, desorption of sulfur (S) atoms during deposition of CGS thin films at elevated temperatures results in the formation of defects and alters the material attributes. Post sulfurization may minimize S deficit, but it is still challenging to control S content due to its high vapour pressure. Therefore, this work investigates the effect of Tellurium (Te) doping during deposition on CGS’s crystallinity and optical properties, expecting relatively low vapour pressure of Te to stabilize the CGS structure. X-ray diffraction reveals the formation of a tetragonal phase indicating a better crystallinity and an enhanced crystallite size. Electrical mobility increased with Te doping, potentially due to the reduced grain boundary scattering with increased crystallite size. The optical bandgap energy of the deposited material decreases from 2.45 eV to 2.00 eV with increasing the concentration of dopant. These results make the CuGa(S,Te)2 a potential absorber material with a tuneable bandgap for solar cell application in a high energy spectrum.

Modification of the structural, linear and nonlinear optical properties of zinc oxide thin films via barium and magnesium doping

In the current work, the structural, linear and nonlinear optical properties of zinc oxide thin films have been modified via barium/magnesium doping for modern optoelectronic applications. Ba/Mg-doped and undoped ZnO thin films were successfully prepared by the spray pyrolysis route. The surface morphology, structures' modification and structural parameters were explored using a field emission scanning electron microscope, FT-IR spectrophotometer and X-ray diffraction techniques, respectively. The XRD analysis shows that Ba/Mg-doped and undoped ZnO thin films possess a crystalline nature with a hexagonal wurtzite structure. The crystallite size of the undoped ZnO nanoparticles is 18.5 nm and varies to 21.4 nm (Ba:ZnO), 23.1 nm (Ba/Mg:ZnO) and 16.4 nm (Mg:ZnO). The optical properties (transmittance, absorbance and reflectance) were measured using a UV–visible spectrophotometer. The optical bandgap (Eg) of ZnO thin film decreases from 3.42 eV to 3.35 eV (Ba:ZnO), 3.25 eV (Ba/Mg:ZnO) and 3.31 eV (Mg:ZnO). The decrease in the Eg values of the doped ZnO films as compared with that of the undoped one is mainly attributed to the created defects and localized states in the bandgap of the host ZnO due to Ba/Mg-doping. Moreover, the major optical parameters (refractive index, distinction coefficient, dielectric constant) are also affected as a result of Ba/Mg-doping. Furthermore, a great effect of Ba/Mg-doping on the nonlinear optical constants (third-order optical susceptibility (χ(3)) and nonlinear refractive index (n2)) and first-order linear optical susceptibility (χ(1) is achieved. The obtained results show that the linear and nonlinear optical properties of ZnO film could be enhanced via Ba/Mg-doping for updated applications in multifunctional modern optoelectronics and high-speed communications.

Synthesis and Characterization of Highly Photocatalytic Active Ce and Cu Co-Doped Novel Spray Pyrolysis Developed MoO3 Films for Photocatalytic Degradation of Eosin-Y Dye

The current work deals with the fabrication of novel MoO3 nanostructured films with Ce and Cu co-doping through the spray pyrolysis route on a glass substrate maintained at 460 °C for the first time. The phase of developed films was approved by an X-ray diffraction study, and the crystallite size was determined between 82 and 92 nm. The optical transmission of the developed films was noticed to be reduced with doping and found between 45 and 90% for all films, and the absorption edge shifted to a higher wavelength with doping. The optical energy gap of the fabricated films was found to be reduced from 3.85 to 3.28 eV with doping. The developed films were used to degrade the harmful Eosin-Y dye under UV light. The system with 2% Ce and 1% Cu-doped MoO3 turned out to be the most effective catalyst for photodegradation of the dye in a period of 3H and almost degrade it. Hence, the MoO3 films prepared with 2% Ce and 1% Cu will be highly applicable as photocatalysts for the removal of hazardous dye from wastewater.

Improved linear and nonlinear optical properties of PbS thin films synthesized by spray pyrolysis technique for optoelectronics: An effect of Gd3+ doping concentrations

In the present article, the pure PbS and different concentrations of Gd doped PbS (Gd:PbS) films were developed using the spray pyrolysis route by growing thin films on the glass substrate. The estimated crystallite sizes were found from 15.5 to 20.8 nm for as-deposited films. The spherical shape morphology of grains was observed by FESEM. The obtained average grain sizes varied from 52.8 to 108.2 nm were obtained from the grain size distributions for 0.0, 0.5, 1.5, and 2.5 wt % Gd: PbS films, respectively. Extinction coefficients of as-deposited films were measured from 0.04 to 0.12 in the range of wavelength 200–2500 nm. Refractive indices of films were obtained from 5.4 to 1.22 in range of 200–2500 nm wavelength. The band gaps of 2.75, 2.64, 2.45, and 3.10 eV for 0.0, 0.5, 1.0 and 2.5 wt % Gd thin films were estimated using Tauc's relation respectively. The values of the dielectric constant, dielectric loss, and optical conductivity were recorded in the range of 1.32–29.6, 0.30–0.61, and 2.34 × 1014–3.08 × 1013 between 200 and 2500 nm wavelengths for as-deposited thin films respectively. The optimum values of linear susceptibility, non-linear susceptibility and refractive index were recorded in the range of 1.23–2.93, 5.21 × 10−10 - 120 × 10−10, 3.54 × 10−9 – 74.2 × 10−9 (esu) between 1.46 and 0.52 eV respectively for as-deposited thin films. The Gd: PbS thin films improve the physical properties and therefore, it becomes suitable candidature for the applications in optoelectronic devices.