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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. [ABSTRACT FROM AUTHOR]

In this research work, we used the Taguchi approach to find the optimal condition of parameters to elaborate nanocrystalline of semiconductor Cu2ZnSnS4 (CZTS) using spray pyrolysis technique. To enhance the optical properties (band gap) of CZTS thin films, we used the Taguchi design of experiments with L 27(36) orthogonal array, analysis of variance (ANOVA) and signal-to-noise ratio (S/N). Six deposition parameters called factors, namely deposition temperature, Cu/(Zn + Sn), S/(Cu + Zn + Sn), Zn/Sn ratios, pressure, and deposition time, were selected. For each factor we set three levels by using the Taguchi method to perform the tests. Applying the Taguchi approach, the analysis of the found results showed that the significant factors are the annealing temperature in air and the S/Metal ratio. The influence of deposition parameters on optical, structural, morphological, and electrical properties are studied. CZTS material synthesis with optimal combination of parameters has been characterized, using an UV–visible spectrophotometer (UV–Vis), X-ray diffractometer (XRD), Raman spectroscopy (RM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and four-point probe method. The analysis of optical properties indicated that the energy gap of the CZTS absorbers is 1.52 eV. XRD data showed the formation of pure kesterite structure with a privileged direction along the (112) plan. Raman spectroscopy confirmed the purity of CZTS by observed peaks at 332 and 660 cm−1, SEM micrograph indicated the uniformity of the films and the homogeneity of the grains, atomic force microscopy (AFM) showed the lattice parameters and grain sizes, and the sheet resistance is fixed at 428,4 (ohm/square). [ABSTRACT FROM AUTHOR]

The semiconductor realization is a very significant stage in gas sensor application. Herein, the Mn3O4 semiconductor was deposited using chemical spray pyrolysis. The effect of deposition temperature on structural, vibrational optical and electrical Mn3O4 thin layers properties were investigated through: X‐ray diffraction, Raman spectroscopy, UV‐visible spectrophotometer, and two points electrometers respectively. The X‐ray diffraction showed the appearance of spinel phase of tetragonal Mn3O4 with strong formation direction along (101) plan and without any secondary phase indicating the formation of pure Mn3O4. The Raman spectroscopy confirmed the results obtained in XRD and certified the high‐quality formation of Mn3O4. In addition, the crystallinity improvement (the increase of crystallite size and the decrease of dislocation density) was caused by the increasing of deposition temperature from 350 °C to 450 °C. Optical properties such as transmittance, absorbance and band gap energy were extracted by UV‐Visible spectrophotometer. Thus, low transmittance, high absorbance and small band gap energy were observed at the highest substrate temperature (450 °C). The electrical conductivity showed good values between 4.83 and 13.89 mS.cm−1. These properties make Mn3O4 an appropriate material to be used as a sensitive layer in gas sensors applications. [ABSTRACT FROM AUTHOR]

Our TiO2 thin films were elaborated using spray pyrolysis technique. The spray solutions were prepared by two titanium precursors: titanium (IV) propoxide and titanium chloride. The elaborated thin films were analyzed with different characterization techniques such as X‐ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and UV–visible spectroscopy. These characterizations showed that the change of precursors from titanium chloride to titanium propoxide has a significant impact on all TiO2 properties. The structural characterizations showed the formation of anatase TiO2 and the crystallization improvement when the precursor changed from titanium chloride to titanium (IV) propoxide, which proves the superiority of our TiO2 thin layers made without any type of annealing in comparison with other previous studies. The SEM images showed an improvement of the surface quality of the TiO2 thin layers with the change of TiO2 precursors' solution. The obtained optical properties confirmed the semiconducting properties of TiO2 prepared by titanium propoxide with a large band gap equal to 3.28 eV and shifted to 3.18 eV. The refractive index increases from ~1.75 to ~2.14, while the porosity decreases. To confirm the experimental results, the Wien2K code, founded on the full‐potential linearized augmented plane wave (FP‐LAPW), has been used. The theoretical study has been done by applying the generalized gradient approximation (GGA), the modified Beck‐Johnson (MBJ) exchange potential, and the local spin density approximation + Hubbard's parameter U (LSDA + U). The theoretical results varied with the variation of approximations. The obtained properties were improved with LSDA + U and acquired the real values of Eg, n, and k for anatase TiO2 (like Eg = 3.214 eV). The obtained experimental and theoretical results could be considered superposable or better than other ones recently published. [ABSTRACT FROM AUTHOR]

The semiconductor's realization is a very significant stage of optoelectronics devices. In this work, an elaboration of the TiO2 semiconductor is made with various solution flow rates via spray pyrolysis. The structural and optical properties of pure TiO2 are investigated with several characterization techniques which include: X‐ray diffraction (XRD), Raman spectroscopy, and UV–vis spectrophotometry. The XRD of elaborated TiO2 layers exhibits nanocrystalline nature with a preferential orientation at the (101), a unique phase of anatase TiO2. The apparition of vibration modes in Raman spectra confirms the TiO2 formation with a single phase. The produced TiO2 has an optical transmission varying from 90% to 70% in the visible wavelength. The energy band gaps are 3.42, 3.32, and 3.28 eV for the TiO2 elaborated at 1, 1.5, and 2 mL min−1, respectively which prove the semiconducting properties of TiO2. All other optical parameters such as refractive index (n), extinction coefficient (k), and dielectric constant (εr, εi) vary with the variation of solution flow rate. These investigations discover that the properties of TiO2 layers can be adjusted by solution flow rate. It seems that the process of spray pyrolysis provides a facile way to control the quality of TiO2 thin layers. [ABSTRACT FROM AUTHOR]

In this study, semiconductor compound Cu2BaSnS4 absorber layer thin films were elaborated by the sol–gel approach associated with dip-coating deposition technique at different dipping speeds. The influence of dipping speed at different speeds of 30 mm/min, 40 mm/min, 50 mm/min, 60 mm/min and 70 mm/min, respectively, on different properties of elaborated films was investigated. X-ray diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), UV–vis spectrophotometry and four-point probe technique were employed to analyze the structural, compositional, morphological, optical and electrical properties. XRD measurements proved the formation of trigonal Cu2BaSnS4 with privileged orientation along the (100) plane. It was seen that crystallites' size of trigonal CBaTS thin films increased with the dipping speed increased from 27.93 to 41.91 nm. Secondary phase BaS2 was observed with CBaTS phase in all films. Raman spectroscopy measurements confirmed the presence of CBaTS films by the Raman peak located at 341 cm−1. EDS analyses confirmed the existence of elements composition present in CBaTS thin films. SEM micrographs showed the increase in uniformity and density of films. Also, the best surface morphology was observed at the film deposited at 70 mm/min. UV–vis spectrophotometry showed that the absorption coefficients are greater than 104 cm−1. Optical band gap of CBaTS thin films decreased from 1.61 to 1.5 eV when the dipping speed increased. The calculated electrical conductivity of CBaTS thin films was found in the range of 0.11–16.66 (Ω. cm) - 1 . These properties are interesting and show that Cu2BaSnS4 thin films can be used as a good absorber in thin film-based solar cells. [ABSTRACT FROM AUTHOR]

In this present work, we applied Taguchi's plan of experimentation as a numerical tool to develop a TiO2 gas sensor. This plan permits us to reduce the number of experimentations and obtain the optimal conditions of factors involved in the development of the sensitive layer. The focal concept is to optimize the TiO2 thin film conductivity by using an L9 (33) orthogonal array based on three important factors of spray pyrolysis deposition (A, concentration of [Ti4+]; B, deposition temperature; and C, spray pyrolysis time). These factors are varied to select the best deposition conditions and to obtain the best conductivity of TiO2 thin films. From the calculation of signal-to-nose ratio (S/N) and the analysis of variance (ANOVA) based on the conductivity values of thin films, the optimal combination of factors is A2B3C3, which corresponds to the concentration [Ti4+] = 0.3 kmol/m3, the deposition temperature T = 500°C and the spray time = 15 min. The validation test confirmed that this combination of deposition parameters is the most optimal to improve the most important TiO2 thin film properties. X-ray diffraction shows a high privileged direction along the (101) plane, large crystallite size of 21.43 nm and low dislocation density of 2.17 × 10−3 nm−2. The Raman modes located at 143 cm−1, 391 cm−1, 512 cm−1 and 633 cm−1 confirmed the purity of anatase TiO2. The images of scanning electron microscopy showed the growth of compact and granular film with an average of grain size of 66.76 nm. The optical analysis showed a transparent semiconductor with large band gap of 3.33 eV. The electrical measurement displayed a good conductivity of TiO2 equal to 280.06 × 10−6 (S m−1). These outcome properties make TiO2 thin film an attractive material for gas sensor applications. [ABSTRACT FROM AUTHOR]

Zinc sulfide thin films are deposited by spray pyrolysis. The growths are varied to attain suitable properties for the application as a buffer layer and electron transport layer in solar cells. All prepared films present a cubic ZnS phase. The 2 min depositions time show a constant transmittance (∼ 94%) in the visible region. Transmittance variations are similar to the crystal quality, and this can be related to the surface morphologies. The band gaps Eg did not show significant variation with deposition times. [ABSTRACT FROM AUTHOR]

In this study, we reported the impact of spray time and substrate temperature on several properties of TiO2 thin layers elaborated by facile and robust spray pyrolysis (SP) technique. The TiO2 thin layers were characterized by the following techniques: X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM) and UV–visible spectrophotometer (UV–Vis). The XRD results demonstrated the pure anatase phase of TiO2 thin layers with the preferential direction along < 101 > direction. The vibration characteristics of TiO2 have been confirmed by Raman vibratory modes located at 143, 396, 518 and 637 cm−1 which certified the formation of a single phase of TiO2 Anatase. The SEM images showed the formation of granular TiO2 layers. The UV–Vis spectrophotometer displayed the semiconducting properties of TiO2 semiconductor, the band gap energy was ranged between 3.10 and 3.30 eV. All parameters investigated in this study confirmed that TiO2 deposited by the inexpensive spray pyrolysis during 25 min at 500 °C had the required properties for gas sensing applications and are in good agreement with those reported in the literature. The sensing properties of the elaborated TiO2 thin films to NO2 showed their high suitability to detect this pollutant gas. [ABSTRACT FROM AUTHOR]

Quaternary semiconductor Cu2NiSnS4 thin film was made by the sol–gel method associated with dip-coating technique on ordinary glass substrates. In this paper, we have studied the impact of dip-coating cycle at different cycles: 4, 5 and 6 on the structural, compositional, morphological, optical and electrical characteristics. CNTS thin films have been analyzed by various characterization techniques including X-ray diffractometer (XRD), Raman measurements, scanning electron microscope (SEM), energy-dispersive X-ray spectroscope (EDS), UV–Visible spectroscopy and four-point probe method. XRD spectra demonstrated the formation of cubic Cu2NiSnS4 with privileged orientation at (111) plane. Crystallite size of cubic CNTS thin films increases from 6 to 9 with augmentation of dip-coating cycle. Raman scattering confirmed the existence of CNTS thin films by Raman vibrational mode positioned at 332 cm−1. EDS investigations showed near-stoichiometry of CNTS sample deposited at five cycles. Scanning electron microscope showed uniform surface morphologies without any crack. UV–Vis spectroscopy indicated that the optical absorption coefficient values are larger than 104 cm−1. Estimated band gap energy of CNTS absorber layers decreases from 1.64 to 1.5 eV as dip-coating cycle increased. The electrical conductivity of CNTS thin films increases from 0.19 to 4.16 Ω cm - 1 . These characteristics are suitable for solar cells applications. [ABSTRACT FROM AUTHOR]

In this present work, we have studied the effect of organic solvents and acetylacetone (Acac) molar ratio on several properties of TiO2 thin films prepared by pneumatic spray pyrolysis (SP). The TiO2 thin films were characterized by the following techniques including the following: X-ray diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM) and UV–visible spectrophotometer. The XRD results showed pure anatase TiO2 thin films with preferential orientation (101) plan, the crystallite size varying between 14.72 and 35.12 nm. The Raman spectroscopy confirmed the formation of the only phase of TiO2 (anatase). The morphological properties were investigated by SEM. The UV–Visible spectrophotometer showed the semiconducting properties of anatase TiO2, and the optical band gap was ranged between 3.17–3.34 eV. The refraction index, the extinction coefficient and the porosity were estimated using transmittance values. The TiO2 thin films have had good properties. They were prepared by low-cost technique, spray pyrolysis, by saving energy and time because the samples were synthesized using air pulverization without using any oxygen sources and without any annealing requires the following: CVD room, low pressure and more time for annealing (Sahoo et al. 2019 in Phys Chem Chem Phys 21: 6198–6206). [ABSTRACT FROM AUTHOR]

CuInS2 thin films were synthesized by spray pyrolysis. The films were characterized using X-ray diffraction, Raman spectroscopy, and spectrophotometer (UV–Vis). The structural studies reveal that CuInS2 thin films are of chalcopyrite phase. The complex dielectric constants (εr and εi), the refractive index (n), extinction coefficient (k), absorption coefficient (α), gap energy (Eg), and the optical conductivity (σ) were calculated. The obtained results are suitable for photovoltaic applications. To confirm our experimental results, a series of Ab initio calculations was performed. The generalized gradient approximation and the mBJ potential for the exchange–correlation potential have been used to calculate the band structure, density of states, charge density, and optical properties of CuInS2. [ABSTRACT FROM AUTHOR]

In this work, we synthesis Cu2ZnSnS4 (CZTS) thin films by sol–gel method associated to dip-coating technique on the ordinary glass substrates. We investigated the effect of dip-coating speed on the structural, morphological, optical and electrical properties of films at various speeds 30, 40, 50 and 60 mm/min, respectively. The films have been characterized by different characterization techniques such as: X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), UV–Visible spectrophotometer and four point probe method. XRD spectra showed pure kesterite CZTS with a preferential orientation along (112) plane. Raman scattering measurement showed the peak at 332 cm−1 correspond to pure CZTS phase. XPS analysis confirmed the presence of Cu, Zn, Sn and S elements on the surface of deposited CZTS. SEM images showed an improvement in density and uniformity with increasing dip-coating speed. The band gap energy is decreased with increasing of dip-coating speed in the range of 1.38–1.45 eV. The electrical conductivity increased between 4.90 and 5.81 (Ω.cm)−1. These characteristics make the deposited CZTS film a suitable material as an absorber layer in photovoltaic devices. [ABSTRACT FROM AUTHOR]

This work presents the preparation of nanostructured zinc oxide (ZnO) thin films doped nickel (Ni) with the molar ratios [Ni]/[Zn] = 0.5; 1; 1.5; 2% M, using low cost spray pyrolysis method. Different characterization techniques were established, such as: X-ray diffraction that showed the hexagonal structure of the films confirmed by Raman spectroscopy. The grain size variations and the morphology according to doping levels were analyzed by scanning electron microscopy. Optical analysis was carried out, the films are transparent and the band gap energy varies opposing to Urbach energy. From experimental data, we observed that 2% Ni doped ZnO exhibited good characteristics and properties compared to pure ZnO and followed by the other samples. The gas testing confirmed the previous concepts, proving that 2% of nickel added to the basic solution enhanced; response/recovery time, response of the sensor and optimal working temperature. This sample demonstrated better selectivity to acetone detection with high response reaching 90, at 450 °C under 100 ppm. [ABSTRACT FROM AUTHOR]

This study aims at synthesizing zinc sulfide (ZnS) thin films using spray pyrolysis method. The effect of the Zn concentration on the physical properties of ZnS is investigated using X‐ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis spectrophotometer, photoluminescence (PL), and Raman spectroscopy. XRD shows a preferential orientation along the (111) direction corresponding to the ZnS cubic structure. Based on the XRD results, it is seen that low zinc concentrations compared to sulfur content can increase the crystalline quality of films. Raman spectra confirm the presence of the ZnS cubic structure observed by XRD and show the presence of sprayed ZnS vibrational modes for all films. PL emission spectrum of ZnS confirms the presence of Zn and S atoms at all molar concentrations. SEM reveals densely packed and uniformly distributed grains with precise shapes. The elemental analysis confirms the growth of stochiometric Zn/S ratio. The optical analysis shows a high transmittance around 88% in the visible range of the solar spectrum with optical band gaps varying from 3.4 to 3.6 eV. These properties are interesting and show that ZnS thin films can be used as buffer layers in thin film solar cells applications. [ABSTRACT FROM AUTHOR]

The structural, mechanical, thermal, electronic and optical properties of inorganic Pb-free double perovskites C s 2 T i X 6 (X = C l , B r , I) compounds are investigated. Using the first-principles with full-potential linearized augmented plane wave (FP-LAPW) method, supported the density functional theory, and therefore the generalized gradient approximation (GGA-PBE) and Hybrid exchange-correlation functionals with and without spin-orbit coupling. The computation of the lattice constants showed an honest agreement between our results and the experimental results and the theoretical data available. Using the three independent elastic constants C 11 , C 12 and C 44 , various mechanical and thermal properties are obtained such as: bulk modules B , shear modules G , Young's modules Y , Pough's ratio B / G , Frantesvich ratio G / B , Poisson's ratio υ , Shear anisotropy character A and Debye temperature Θ D for C s 2 T i I 6 , C s 2 T i B r 6 and C s 2 T i C l 6 respectively. Our calculated elastic constant results show that C s 2 T i I 6 , C s 2 T i B r 6 and C s 2 T i C l 6 are mechanically stable, anisotropic and ductile in nature. Furthermore, the C s 2 T i C l 6 compound has the highest Debye temperature, which indicates the highest melting temperature. The electronic band structures reveal the semiconductor conductivity of the three compounds, with a band gap suitable for photovoltaic applications, within the range of 1.5–2.96 e V. Finally, C s 2 T i C l 6 (X = C l , B r , I) HPs compounds exhibit excellent optical properties like optical absorption, conductivity and refraction index. • The calculated elastic constant results show that C s 2 T i I 6 , C s 2 T i B r 6 and C s 2 T i C l 6 are mechanically stable, anisotropic and ductile in nature. • The calculation of optimized lattice constants indicate that our results are in good agreement with the experimental data and theoretical data available. • The electronic band structures reveal the semiconductor conductivity of the three compounds, with a band gap suitable for optoelectronics applications. • The results of optical properties indicate that the C s 2 T i C l 6 (X = C l , B r , I) halide perovskites are a promising material for photoelectric conversion. [ABSTRACT FROM AUTHOR]

A high transparent Cu doped ZnS thin films were successfully deposited by the spray pyrolysis method at different deposition times. X-ray diffraction (XRD) patterns showed that all films were monocrystalline with the wurtzite crystal structure. A small variation in the optical band gap for all films was observed, indicating that the variation of deposition time doesn't affect strongly the bandgap. The average crystallite size of prepared thin films was calculated using Scherrer's formula and found to be in the range 29–33 nm. The crystallite size and microstrain of samples were investigated. Raman scattering spectra indicate the presence of different phonon modes and different peaks of Photoluminescence spectra for all samples which confirmed the presence of the elements Zn, S, and Cu with a comparison to the previous reported work. Using scanning electron microscope (SEM) images of elaborated thin films show a spherical with agglomeration. UV–visible measurements revealed height transmittance in the visible range for all growth time. [Display omitted] • The influence of Deposition time on physical properties Cu doped ZnS thin films using spray pyrolysis. • The structural and optical study using XRD, Raman and photoluminescence of Cu doped ZnS thin films. • Optical properties demonstrate the use of the materials in Photovoltaic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this study, the effect of controlled conditions on the optical properties of tin monosulfide (SnS) thin films was successfully investigated by the chemistry spray pyrolysis deposition method on glass substrates. The Taguchi model is reported to find the most important factor for the deposition process of SnS thin films with orthogonal L9 (34) alignment. We also derive the band gap energy from transmittance data used to determine S/N relation. The selected influencing parameters are: tin-[Sn-] and sulfide-[S] concentrations, deposition substrate temperature (°C) Td and deposition time (min). The results show that the deposited film has a uniform, pure orthorhombic SnS phase and smooth morphology. Energy dispersive X-ray spectroscopy (EDS) utilizes the chemical composition of the prepared layers. In addition, the UV–Vis transmittance spectrum of the obtained film via the optimum conditions showed low transmittance in the visible region. Also, the SnS thin film shows the best gap interstitial energy of 1.52 eV. However, the SnS thin films produced by optimizing the Taguchi model display good optical properties and suggest that SnS thin films may be one of the potential solar cell absorbers in photovoltaic devices. • Effect of controlled conditions on the optical properties of Tin monosulfide (SnS) thin films was successfully investigated by the chemistry spray pyrolysis deposition method on glass substrates. • Optimization of the preparation conditions based on Taguchi design to elaborate The SnS thin films via the low-cost spray pyrolysis technique. • Elaboration via the optimal conditions and study of structural, morphology and optical properties of SnS thin films. • X-ray diffraction and Raman spectroscopy show the formation of pure SnS thin films with a good morphology. • The motivating optical properties show that the SnS absorber layers can be low-cost and suitable material for the photovoltaic solar cells. [ABSTRACT FROM AUTHOR]

Cu 2 XSnS 4 (X = Mn, Fe, Co) semiconductor represent one of the most promising quaternary family for the photovoltaic devices. For this purpose, a comparative study of structural, electronic, linear/non-linear optical and thermoelectrical properties of Cu 2 XSnS 4 based on the first-principles calculations and Boltzmann theory was done, using the generalized gradient approximation GGA with applying the Hubbard on-site coulombic correction to Mn, Fe and Co cations. The computation of the lattice constants shows a good agreement with the experimental results, also the simulation of X-ray diffraction (XRD) spectra shows that the compounds have crystallized in the polycrystalline kesterite form with a preferential orientation along (112) plane. The GGA + U method offering that CMTS, CFTS and CCTS materials exhibit a duality ferromagnetic semiconductor behavior. The optical properties showed good optical absorption in order of 20 and 30 (104 cm−1) for the three compounds, and a high optical conductivity in the visible range. Thus, the non-linear optical properties as well as suitable optical band gaps of about 1.44–1.56 eV confirms the applicability of CMTS, CFTS and CCTS materials as absorbent layers in photovoltaic solar cells. In addition, the thermoelectric properties such as electrical conductivity (σ / τ) , Seebeck coefficient (S) and power factor (S 2 σ / τ) as a function of temperature were investigated using Boltztrap package, we have found that CMTS, CFTS and CCTS kesterite materials exhibit p-type behavior and good thermoelectric transport properties in the temperature range of 300 - 800 K , therefore, we expect these materials to be potential candidates for clean energy applications. • The electronic properties shown that Cu2XSnS4 (X = Mn, Fe, Co) materials have a duality ferromagnetic semiconductor, direct and quasi-direct band gap character. • The linear and nonlinear optical properties show that the Cu2XSnS4 (X = Mn, Fe, Co) an excellence materials for photonic and photovoltaic applications. • The thermoelectrical properties show that the Cu2XSnS4 (X = Mn, Fe, Co) materials to be potential candidates for clean energy applications. [ABSTRACT FROM AUTHOR]