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In this paper, thin films of Ag2ZnSnS4 (AZTS) were spin-coated on to ordinary glass substrates and annealed at temperatures ranging from 300 to 375 °C without sulfurization. Characterization techniques like X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Raman Spectroscopy (RS), Energy Dispersive X-ray Spectroscopy (EDS), and UV-Vis spectrophotometry were used to investigate the different physical properties of AZTS thin films. The analyses of XRD and Raman patterns showed that AZTS thin films have a polycrystalline structure with peaks corresponding to the pure tetragonal phase. SEM micrographs showed a nearly uniform, dense, and compact surface morphology for AZTS thin film annealed at 375 °C. The films showed absorption coefficients greater than 104 cm−1 with band gaps found between 1.50 and 1.59 eV. These properties make AZTS thin films a suitable absorber layer for photovoltaic applications. Highlights: Synthesis and characterization of Ag2ZnSnS4 thin films by sol-gel method associated to spin coating technique. Study the effect of annealing temperature on some physical properties. XRD data and Raman scattering measurements indicated the formation of pure Ag2ZnSnS4. Compositional and morphological show that Ag2ZnSnS4 thin films can be suitable for photovoltaic applications. [ABSTRACT FROM AUTHOR]

In this review, the most recent revelations in the possibilities of integrating various solar collectors with thermoelectric generators (TEGs) and their main promising results are presented. These combined structures produce the normal (thermal, electrical) energy generated by the solar panel with an additional electrical power resulting from the combination with TEG modules, implying a better exploitation of solar radiation. At the beginning, the basic principles of combined solar thermal and electrical conversion systems, including the photovoltaic (PV) panel combined with the thermal collector (Th) constituting the PV/Th design, are summarized. Second, a detailed discussion on the existence and material varieties of thermoelectric generators, recent industrial applications, and parameters affecting the efficiency of thermal-electric conversion are reported. Then, recent feasibility analyses, experimental applications, types, and performance now of photovoltaic-thermoelectric (PV/TE) are reviewed, while TEG convert heat and thermal energy. Subsequently, considered and discussed is contemporary research on the utilization of thermoelectric generators in various stationary and concentrating solar thermal collectors and processes. An extensive examination of the key technical, practical, and experimental aspects of tri-generation solar hybrid systems integration is also summarized. This paper is therefore a very helpful reference for future research in the discipline of solar (PV, Th, PV/Th)-TE and its applications. [ABSTRACT FROM AUTHOR]

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]

Herein, the cobalt oxide thin films are elaborated by spray pyrolysis technique. The effect of temperature of substrates on several properties of cobalt oxide is studied. The thin layers are characterized by using X‐ray diffraction (XRD), Raman spectrometry (RS), and UV–vis spectrophotometer. The XRD analysis shows that Co3O4 thin layers have been formed along <111> preferential orientation. The RS displays the characteristic vibration modes of cobalt oxide phase, which confirms the formation of a single phase of spinel Co3O4 thin layers. The UV–vis spectrophotometer allows us to investigate the optical properties such as the absorbance, the transmittance, and the optical bandgap. The variation of electrical properties with the variation of temperature deposition confirms the high impact of the effect that study to make the cobalt oxide an important candidate for gas sensor devices. [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]

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]

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]

The production of thermal energy by solar water heater (SWH) systems is an idea, which has been analyzed and applied for many years. This paper presents a numerical simulation of a new hybrid SWH, in which two tubular thermoelectric generators (TTEGs) and a small water turbine are used to generate more additional electrical energy. The small water turbine is installed between the outlet of the four absorber tubes and the inlet of the water tank in order to generate more electrical energy from the cold‐water motion. Furthermore, the use of a temperature adjustment concept and an optical concentrator shows many significant improvements on the thermal and electrical performance of the new system. Our main results shows that the overall maximum electrical power of two TTEGs was approximately 348.073 W, corresponding to 2.72% of their overall maximum electrical efficiency. Also, the maximum thermal efficiency of the new system reached to 86.09% with an overall hot water quantity of 1548.57 L/d. The electrical energy produced by the small water turbine is about 89.467 W for a cold‐water flow rate of 3 kg/s. [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]

Semiconductor compounds Cu2MnSnS4 absorbers materials were synthesis by the sol–gel approach and deposited using dip-coating technique on ordinary glass substrates. In this work, we have studied the effect of various annealing temperature such as: 400 °C, 425 °C, 450 °C and 475 °C for 1 min on the structural, compositional, morphological, optical and electrical investigations. CMnTS thin films have been characterized by some analyse techniques such as: X-ray diffractometer (XRD), Raman spectroscopy, dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), UV–visible spectroscopy and four-point probe method. XRD data proved the formation of stannite Cu2MnSnS4 with privileged direction at (112) plane. Crystallite size of stannite CMnTS thin films increased with the increase of annealing temperature from 7.26 to 11.57 nm with annealing temperature augmented. Raman experiments complete the confirmation of stannite CMnTS thin films existence by Raman vibrational modes located at 288 cm−1 and 330 cm−1. EDS analysis demonstrated close-stoichiometry of CMnTS thin films annealed at 450 and 475 °C. SEM images demonstrated the improvement of crystallinity and uniformity of surface morphologies when annealing temperature is 475 °C. UV–visible spectroscopy indicated that the transmittance spectra increased when annealing temperature increased in the wavelength range of 450–850 nm. The absorption coefficient values are higher than 104 cm−1, the approximated bandgap of CMnTS absorber material decrease in the range of 1.72–1.5 eV when annealing temperature increased. The electrical resistivity of CMnTS thin films decrease from 4.77 to 0.85 (Ω.cm). These properties are appropriate for photovoltaic solar cells applications. [ABSTRACT FROM AUTHOR]

Quaternary semiconductor Cu2ZnSnS4 absorber material was synthesized by the sol-gel method deposited by the dip-coating technique on ordinary glass substrates. In this study, we have investigated the effects of dip-coating cycle at different cycles: 2, 4 and 6, and annealing temperature at various temperatures: 300, 325 and 375 °C on the structural, morphological compositional, optical and electrical properties. The films have been characterized by different characterization techniques such as X-ray diffractometer (XRD), Raman scattering experiments, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), UV–visible spectrophotometer and four-point probe method. XRD patterns indicated kesterite CZTS with preferential orientation along (112) plane, Cu2-xS, SnS2 and SnS secondary phases were observed with CZTS phase in some samples. The pure CZTS phase was formed for the sample annealed at 375 °C and sample deposited at 2 cycles. Raman spectroscopy confirmed the presence of CZTS thin films in all samples using Raman characteristic peak at 332 cm−1. EDS analysis showed near-stoichiometric CZTS thin films. (SEM) images showed the uniform and dense surfaces morphologies. The gap energy is estimated from absorbance data by using absorption spectra fitting (ASF). The optical band gap decreases with the increasing of dip-coating cycle in the range of 1.33–1.44 ∓ 0.01 eV and also increases with the increasing of annealing temperature in the range of 1.38–1.47 ∓ 0.01 eV. The electrical sheet resistance increased from 2.60 ∓ 0.01 to 4.67 ∓ 0.01 × 103 (Ω/square) when the annealing temperature increased and decreased when the dip-coating cycle increased in range of 0.99 ∓ 0.01 and 1.19 ∓ 0.01 × 103 (Ω/square). These characteristics are suitable for solar cells applications. [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]

This paper presents the optimal configuration of parameters for the elaborated Cu2ZnSnS4 (CZTS) absorber layer, using the sol–gel method associated with dip-coating technique on ordinary glass substrates. Taguchi design of experiments with L27 (38) orthogonal array, a signal-to-noise (S/N) ratio, and an analysis of variance (ANOVA) were used to determine the best optical properties for photovoltaic applications (optical bandgap energy) of CZTS thin films. Eight factors named annealing temperature, Cu/(Zn+Sn) ratio, Zn/Sn ratio, S/metal ratio, number of pre-annealing and dip coating, dip-coating cycle, annealing time, and dip-coating speed were chosen. To conduct the tests, we apply Taguchi method; three levels were fixed for each factor. The most important factors of the deposition approach on the optical properties of the fixed as-synthesized CZTS films were determined. The analysis of the obtained results indicated that the important parameters are the Zn/Sn ratio and annealing temperature in air by employing Taguchi approach. A validation test is also carried out to check whether the found optimal combinations of the parameter are correct. CZTS thin-film synthesis with optimal conditions has been characterized, using an X-ray diffractometer (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), UV–visible spectrophotometer, and four-point probe method. XRD data show a kesterite structure with a preferential orientation along the (112) plan; UV–visible spectrophotometer indicated that the bandgap energy of the CZTS thin film is 1.51 eV and a cross section showed the suitable film thickness in the order of ~1.80 µm. Highlights: Synthesis of CZTS thin films by sol gel associated to the dip-coating technique. Application of Taguchi method to optimize the sol gel dip-coating process of the semiconductor CZTS with good optical properties. The statistical analysis (ANOVA) has the capacity to give information about certain statistical parameters. The CZTS thin film elaborated with optimal parameters has good morphological optical and electrical properties. [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]

The obtained minima T SB m sb and maxima T SB M sb values have been used to estimate the film thickness using the envelope method. In this Reply we would like to provide the interference observed in the transmission spectrum and used of the maxima and minima in the envelope method to correct the misunderstanding of our transmittance results. [Extracted from the article]

Copper-indium-gallium-disulphide (CuInGaS) is a promising absorber material for thin film photovoltaic. In this paper, CuInGaS (CIGS) thin films have been prepared by chemical spray pyrolysis method onto glass substrates at ambient atmosphere. Structural, morphological, optical and electrical properties of CuInGaS films were analysed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-Vis spectrophotometer and Hall Effect measurement, respectively. The films exhibited single phase chalcopyrite structure. The strain and dislocation density decreased with increase of spray time. The grain size of the films increased from 4.45 to 9.01 nm with increase of spray time. The Raman spectrum indicated the presence of the principal chalcopyrite peak at 295 cm $$^{-1}$$ . The optical properties of the synthesized films have been carried out through the measurement of the absorbance spectrum. The optical band gap was estimated by the absorption spectrum fitting (ASF) method. For each sample, the width of the band tail ( $$E_\mathrm{Tail}$$ ) of CuInGaS thin films was determined. The resistivity ( $$\rho$$ ), conductivity ( $$\sigma$$ ), mobility ( $$\mu$$ ), carrier concentration and conduction type of the films were determined using Hall Effect measurements. The interesting optical properties of CuInGaS make them an attractive material for photovoltaic devices. [ABSTRACT FROM AUTHOR]

Cu2ZnSnS4 (CZTS) thin films have been prepared via sol-gel method and deposited on ordinary glass substrates by dip-coating technique. The chemical composition of Cu/(Zn + Sn) ratio was varied between 0.85, 0.95 and 1.05 to study its effect on structural, optical, morphological, compositional and electrical properties of deposited films. The films were investigated using different techniques such as X-ray diffractometer (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), UV-vis spectrophotometer and four-point probe method. The X-ray diffraction showed the single kesterite phase with the preferential orientation along (112) plane. The crystallites size was found to be between 6.95 and 9.30 nm. Raman scattering measurements for CZTS films deposited at Cu/(Zn + Sn) equal to 0.85 and 1.05 were confirmed the presence of pure CZTS phase by the characteristic peak at 332 cm−1. The morphological properties show a dense surface morphology and the elemental composition indicates CZTS films with a near-stoichoimetric composition. The optical properties were calculated using transmittance and absorbance data in the wavelength range between 450 and 850 nm. The obtained band gap energy values were found to be between 1.41 and 1.47 eV. The electrical sheet resistance showed values between 0.68 and 1.07 × 103 Ω square−1. A best sheet resistance and favorable optical band gap make our dip-coated CZTS thin films suitable to be used as an absorber layer for photovoltaic applications. [ABSTRACT FROM AUTHOR]