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Nickel sulfide (NiS) thin film has been deposited on glass substrates by spray-pyrolysis at 325 ± 5 °C. The precursor aqueous solution was synthetized using hexahydrated nickel nitrates and thiourea. The structural, morphological, optical and electrical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy and four probes electrical measurements. The XRD analysis confirmed the hexagonal structure of NiS thin film, which was found to crystalize along [010] direction with an average crystallites size of 10.5 nm. The lattice parameters are a = b = 3.420 Å and c = 5.300 Å in the space group P63/mmc. The optical properties of the films were investigated through the transmittance and the reflectance measurements. The results revealed that the material exhibits a direct optical band gap of 1.03 eV. The elementary composition analysis confirmed the presence of Ni and S with a stoichiometry ratio (Ni/S) of 1.05. The morphology analysis revealed a homogenous crack-free, compact appearance and a granular surface in all scanned areas. The average roughness of the surface was 6.48 nm. On the other hand, the film exhibits a high electrical conductivity ca. 1.10 × 105 S/cm at room temperature. The above results show that the prepared NiS in this study has a good crystallization, dense morphology, good stoichiometric ratio and high conductivity; therefore, it stands as a potential candidate for application in supercapacitors as an electrode material.

The present study reports on the deposition of Nickel sulfide (NiS) thin films on glass substrates by spray-pyrolysis at 300 ± 5 °C with different concentrations of nickel precursor (0.03, 0.05, an...

La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF) cathode perovskite prepared by a Pechini method deposited on ceria co-doping Ce0.8Sm0.17Ln0.03O1.9 (LnSDC), with (Ln = La, Y, and Nd) electrolytes was successfully prepared by the solid-state reaction method. In this preparation process, thick and thin films of LSCF were deposited upon dense Ln-doped ceria LnSDC electrolytes after 5 and 3 spin-coating and dip-coating cycles, respectively. Two layers of LSCF were deposited by screen-printing in order to obtain thick cathode films. After deposition, some structural and morphologic characterizations, such as X-ray diffraction analysis and scanning electron microscopy, have been conducted to understand the properties of the elaborated samples and to study the impact of doping on these properties. Electrochemical impedance spectroscopy measurements on symmetric cells were also performed to investigate the employability of L0.6Sr0.4Co0.8Fe0.2O3-δ as a cathode material deposited upon LnSDC electrolytes for intermediate-temperature solid oxide fuel cells (IT-SOFC). According to what was available and inferred after studying the images from a scanning electron microscope, no cracks or significant segregation were detected in the LSCF/LnSDC interface. This behavior is consistent with the good thermal expansion compatibility between the two materials. Electrochemical impedance spectroscopy investigations at 700°C, indicate relatively low area-specific resistance between 0.048 and 0.1 Ω cm2 for all symmetrical cell LSCF/doped electrolyte/LSCF. All the cells were previously sintered above 1400°C, in air. All these results showed that L0.6Sr0.4Co0.8Fe0.2O3- δ can stand as a potential candidate for new cathode material in IT-SOFCs.

Pristine and Cobalt (Co)-doped MoO3 nanofilms were synthesized on glass substrates using the spray pyrolysis method. The nanometric pristine MoO3 films were prepared from the 10−2 M.L-1 solution of ammonium molybdate tetrahydrate [(NH4)6Mo7O24,4H2O] in distilled water. Co-doping at 0.5, 0.75 and 1% was achieved by adding cobalt (II) chloride hexahydrate (Cl2CoH12O6) in the pristine solution. The structure and the morphology of the films were investigated by means of X-ray diffraction and atomic force microscopy: two pronounced (020) and (040) peaks corresponding to the orthorhombic structure phase of α-MoO3 were detected. The AFM observations revealed the formation of micro-plates, parallel to the surface plane, with a roughness ranging from 33 nm to 54 nm. Optical properties were investigated through reflectance, transmittance and photoluminescence measurements. The optical band gap, the Urbach energy and the refractive index were deduced from these measurements. The presence of oxygen vacancies was revealed from the interband transitions in the blue and green domains. Co-doped MoO3 nanofilms showed ferromagnetic behavior. The photocatalytic degradation of an aqueous solution of methylene blue (MB) under UV irradiation, in the presence of Co-MoO3 nanomfilms, has been carried out using UV–vis spectrometery: the intensity of the absorption peak recorded at 660 nm decreased with the increase of the UV-illumination time while the color of the initial MB solution was drastically waned.

Quaternary oxides based on strontium, iron, and molybdenum elements such as Sr2FeMoO6 (SFMO) and its analog n = 2 Ruddlesden-Popper (R-P) phase Sr3FeMoO7 were synthesized using chemical spray pyrolysis deposition technique. Optical band gap values, thermal conductivity and thermal diffusivity of both spray-deposited films were investigated. The results confirm that the above properties are considerable factors in forecasting the appropriate perovskite compound for future thermal barrier coating applications.

Nickel molybdate (NiMoO4) thin film has been prepared by the spray pyrolysis method, using nickel chloride hexahydrate (NiCl2·6H2O) and ammonium molybdate tetrahydrate [(NH4) 6Mo7O24·4H2O] as precursors in the aqueous starting solution. First, the structure and the surface morphology characterizations were carried out by scanning electron spectroscopy (SEM), Raman and X-ray diffraction (XRD) techniques. Structural analysis by using XRD technique shows that the NiMoO4 thin film crystallizes in the monoclinic phase, mainly orientation along (110), (021), ( $${\bar{2}}04$$ ), (220), (150) and ( $${\bar{1}}52$$ ), directions. In addition to these studies, the stoichiometric composition has been reached by the energy dispersion analysis technique. Second, the optical properties have been studied by means of the reflectance and the transmittance spectra, in the wavelength range of 300–1800 nm. This study shows a direct transition of this ternary oxide with an optical bandgap about 3.12 eV and Urbach energy EU in the order of 663 meV. Finally, the photoluminescence emission spectrum of the NiMoO4 thin film showed emissions peaks in the violet and blue regions and others emission related to some defects in the prepared film.

This paper highlights some physical investigations on GO-doped ZnO thin films synthesized using zinc acetate dehydrate isopropyl alcohol and graphene oxide (GO) as doping element in a starting solution using a mini-spray pyrolysis process. These films, with thicknesses less than 400 nm, crystallize in hexagonal wurtzite structure with a preferential orientation according to (002) direction. The morphological characterization revealed a good homogeneity at the surface with good dispersion of graphene nanoparticles over the entire surface, especially for 2% GO doping. The refractive index and thickness of ZnO:GO thin films have been calculated using the envelope method. A decrease in the refractive index with doping was observed which indicates an increase of free carriers. In addition, band gap and Urbach energies were also deducted from the absorption coefficient. Indeed, this layer provides an increase in the dielectric constant e2 in the IR range, which is a proof of creating free electrons. Finally, the 2% GO doping gives the best optoelectrical properties of ZnO thin films which can be used in a forthcoming application for future optoelectronics.

This paper deals with the results on the structural, electrical, vibrational and optical properties of LaMn1−xNixO3 (0 ≤ x ≤ 0.3) thin films prepared by the spray pyrolysis technique on glass substrates at 460 °C using (LaCl3·7H2O), (MnCl2·4H2O) and (NiCl2·6H2O) as precursors. First, XRD analysis shows an orthorhombic structure of all prepared thin films. Second, room temperature Raman spectra showed broad and intense bands characteristic of LaMnO3 parent compound modes. An important shift to higher frequencies was observed and attributed to disorder induced by Ni composition and Frenkel defects associated to the formation of vacancy and interstitial oxygen sites. The optical measurements show that the optical band gap energy value varies sparsely in terms of Ni content. On the other hand, the electric conductivity measurements were investigated using the impedance spectroscopy technique in the frequency range 5 Hz–10 MHz at various temperatures (410–500 °C). AC conductivity of LaMn1−xNixO3 thin films is found to follow the Jonsher law. The temperature dependence of the AC conductivity is consistent with the correlated barrier-hopping model with activation energy Ea varying in (0.70–1.29) eV domain. Finally, the magnetic hysteresis loops of such films exhibit obvious ferromagnetic behavior with a high dependency with Ni content particularly the coercivity value (Hc) increases with Ni concentration.

We report on the photocatalytical properties of pure and barium-doped nickel oxide nanofilms synthesised on glass substrates using a simple spray pyrolysis method. The nanofilms were prepared from ...

This work covers some physical properties of Sr-doped NiO sprayed thin films at various concentrations (0 to 4%) prepared on glass substrates. Structural properties by using X-ray diffraction (XRD) show that all films have a cubic structure with (111) orientation. The stress, estimated by adjusting the XRD diffraction peaks increases with the doping concentration. Also, the grain size decreases with the doping concentration. On the other hand, the stacking fault probability has been discussed in terms of Sr doping level. The surface morphology of NiO:Sr thin films were examined by AFM observations. The optical constants (refractive index and extinction coefficient) were obtained by reflectance and transmittance measurements. This optical measurements show that the optical band gap is around 3.8 eV. PL measurements show mainly the transition band in UV blue and green domains related to the band-to-band transition and some defects in these prepared thin films. Finally, the advances in the actively studied photocatalysts that are emerging as effective alternate for nickel oxide based photocatalysts is also discussed.

This work highlights some physical properties related to the influence of aluminum, tin and copper incorporation on nanostructured zinc oxide (ZnO:M; M:Al, Sn and Cu) thin films prepared by ultrasonic spray pyrolysis technique (USP) on glass substrate at 350±5 °C. For the as-grown layers, M- to Zn-ratio was fixed at 1.5 %. The effects of metal doping on structural, morphological, optical and electrical properties were investigated. X-ray diffraction pattern revealed that the as-prepared thin films crystallized in hexagonal structure with (0 0 2) preferred orientation. The surface topography of the films was performed by atomic force microscopy. AFM images revealed inhibition of grain growth due to the doping elements incorporation into ZnO matrix, which induced the formation of ZnO nanoparticles. Optical measurements showed a high transparency around 90 % in visible range. Some optical parameters, such as optical band gap, Urbach energy, refractive index, extinction coeffi-cient and dielectric constant were studied in terms of doping element. Particularly, dispersion of refractive index was discussed in terms of both Cauchy and single oscillator model proposed by Wemple and DiDomenico. Cauchy parameters and single oscillator energy E0 as well as dispersion energy Ed were calculated. Finally, electrical properties were investigated by means of electrical conductivity and Hall effect measurements. The measurements confirmed n type conductivity of the prepared thin films and a good agreement between the resistivity values and the oxidation number of doping element. The main aim of this work was the selection of the best candidate for doping ZnO for optoelectronics applications. The comparative study of M doped ZnO (M:Al, Sn and Cu) was performed. High rectifying efficiency of the Al/n-ZnO/p-Si/Al device was achieved and non-ideal behavior was revealed with n > 4.

Thin films of Molybdenum trioxide (MoO 3 ) were deposited on glass substrates by the spray pyrolysis at 500 °C and the samples were then exposed to gamma γ radiation doses by 60 Co radioisotope at different doses (0.1, 10 and 50 kGy). The effects of gamma irradiation on the properties of MoO3 thin films were investigated. The XRD pattern and Raman spectroscopy of as-deposited MoO 3 samples show an orthorhombic structure related to α-MoO 3 with (0k0) preferred orientations. Uv‐vis spectra were studied to investigate the transmission measurements of MoO 3 films. The optical energy band gap and Urbach energy were found to be gamma-dose dependent. Photoluminescence measurements at room temperature using 300 nm wavelength excitation were investigated. SEM images indicate the formation of α-MoO 3 nanorods.

The electronic structure, elastic constants, and magnetic properties of lanthanum cobaltite oxide $$\hbox {La}_{4}\hbox {Co}_{3}\hbox {O}_{9}$$ compound, which crystallizes in orthorhombic space group Pnma, are investigated theoretically for the first time using the full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory plus Hubbard correction term (DFT $$+$$ U). The calculated equilibrium lattice constants and fractional atomic coordinates are in a good agreement with available experimental data. Our result for the formation energy and elastic constants confirms that the predicted $$\hbox {La}_{4}\hbox {Co}_{3}\hbox {O}_{9}$$ is mechanically stable. This compound is found to be ductile in nature in accordance with Pugh’s criteria. The anisotropy factors ( $${A}_{1})$$ , ( $${A}_{2})$$ , and ( $${A}_{3})$$ of $$\hbox {La}_{4}\hbox {Co}_{3}\hbox {O}_{9}$$ material are also predicted through the elastic constants. The electronic band structures show metallic behavior; the conductivity is mostly governed by Co-3d and O-2p states. The total magnetic moments of the tetrahedral ( $$\hbox {CoO}_{4})$$ and octahedral ( $$\hbox {CoO}_{6})$$ environments are, respectively, 2.502 $$\mu _{B}$$ and 2.874 $$\mu _{B}$$ , which are consistent with the experimental measurements.

This work covers some physical investigations on (Co, Ni) codoped molybdenum oxide thin films deposited on glass substrates at 460 °C by the spray pyrolysis technique. The effects of Co and Ni contents on the structural, morphological, optical and magnetic properties of these films were studied using several physical investigations. First, X-ray diffraction analysis revealed the formation of an orthorhombic structure related to α-MoO3 allotropic phase with (020) and (040) preferred orientations. Also, the scanning electron microscopy (SEM) micrographs showed the enhancement of the surface roughness of MoO3 films by cobalt and nickel concentrations. Second, the optical investigations through reflectance and transmittance measurements indicated a direct transition of all prepared thin films with a remarkable increase of the optical band gap from 3.70 to 3.95 eV with increasing both Co and Ni elements. Finally, the magnetic measurements at room temperature revealed a ferromagnetic behavior of Co and Ni codoped MoO3 films. A ferro-diamagnetic transition phenomenon was occurred for codoped film at Ni 2%and Co 2%.

CoNi2S4 ternary sulfide thin films are deposited on glass substrates by spray pyrolysis at 250 °C using an aqueous solution of chloride hexahydrate (NiCl2,6H2O),tin chloride hexahydrate (CoCl2, 6H2O) and thiourea (SC(NH2)2) (ACROS pure more than 99.0%). Structural study using X-ray diffraction are allowed; lattice parameters and structural defects where studied. Morphological properties are carried out by using both AFM and SEM observations. Optical properties are performed by means of transmittance and reflection measurements as well as photoluminescence measurements. On the other hand, electrical properties are investigated in terms of electrical conductivity, free carrier and relaxation time at different temperatures through Hall effect and four probes measurements. This investigation shows a metallic behavior of this current II-IV2VI4 ternary compound. Finally, the advances in the actively studied electrode that are emerging as effective alternate for CoNi2S4based cyclic voltammetry are also discussed.

Lithium-doped zinc oxide thin films (ZnO:Li) at different percentages (0–4%) were deposited on glass substrates at 460 °C using the spray pyrolysis technique. The effect of lithium content on the structural, morphological and optical properties of ZnO:Li thin films was investigated. First, X-ray diffraction study revealed that undoped and Li-doped ZnO thin films crystallize in hexagonal wurtzite structure with a preferred orientation of the crystallites along (002) direction. The scanning electron microscopy (SEM) showed a clear hexagonal-shaped granular onto the surface of such films. Indeed, the averaged grain size, visualized by SEM, varied from 100 nm, for undoped ZnO, to 200 nm for ZnO:Li 4%. Second, the optical analysis by means of the transmittance and the reflectance measurements revealed that in UV–Vis domain, the average transmittance of the ZnO:Li thin films was 75%, while the average reflectance was

Thin films of bismuth sulfide (Bi 2 S 3 ) have been electrochemically deposited on indium–doped tin oxide substrates from aqueous solutions of Bi(NO 3 ) 3 , ethylene diamine tetraacetic acid (EDTA) and Na 2 S 2 O 3 . The structural properties of the films were characterized using X–ray diffraction and high–resolution transmission electron microscopy analyses. The film crystallizes in an orthorhombic structure of Bi 2 S 3 along with metallic bismuth. Thermal annealing of the prepared film in sulfur atmosphere improves its crystallinity and cohesion. The band gap values of the deposited film before and after annealing at 400 °C were found to be 1.28 and 1.33 eV, respectively.

Cadmium doped Nickel oxide thin films with ratio [Cd]/[Ni] = 0%, 1%, 2%, 2% and 4% were successfully prepared on glass substrates using spray pyrolysis technique at 460 °C. The effect of Cd doping on structural, morphological and optical properties was investigated. First, XRD studies reveal that all the films are polycrystalline with cubic structure and exhibit (111) as preferential orientation. Raman study shows the presence of bands corresponding to NiO structure. Cd is well incorporated in the host lattice without destroying the crystal structure. The surface topography of these films was performed by the atomic force microscopy. Second, the optical transmittance spectra of all films showed high transparency (∼80%) in the visible region. the band gap energy of the films varies from 3.89 to 3.80 eV with the cadmium content. Also, the effect of the cadmium incorporation in NiO matrix is studied in terms of Urbach energy. Finally, Cd-doped NiO thin films have been tested as sensitive films against ethanol vapor at different temperatures. The 3.0 wt% Cd-doped NiO based sensor showed excellent sensitivity toward 0.1% ethanol at the operating temperature of 100 °C.

In this paper, thin films of lithium-doped zinc oxide (ZnO: Li) were prepared by spray pyrolysis in a monophase hexagonal wurtzite structure as shown by X-ray analysis. Rietveld refinement of the X-ray diffraction diagram was applied to calculate the crystalline structure parameters. Impedance spectroscopy, electrical conductivity and dielectric measurements, at various temperatures 340–440 °C and in a frequency spectrum from 5 Hz to 1 MHz, were performed using the EC-Lab V10.12 system. During the electrical conduction processes in the sample, the physical parameters of ZnO:Li thin films such as dielectric constant, relaxation frequency and electrical conductivity σac and σdc, were examined. In addition, AC conductivity analysis resulted in a power law (σac = ωs). Obviously, the temperature dependence of the exponent s fitted well with the correlated barrier hopping (CBH) model proposed by Elliott. Finally, the dependence of conductivity and dielectric constants with frequency and temperature was discussed.

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This paper reports the structural, the, optical, the electrical and electrochemical properties of Ni3Sn2S2 sprayed thin film. This ternary compound thin film was prepared by a simple spray pyrolysis method on ordinary cleaned glass substrate at 250 °C by using nickel chloride hexahydrate, tin chloride hexahydrate and Thiourea. XRD analysis showed that Ni3Sn2S2 crystallized in rhombohedra structure belonging to R-3 m (166) space group. Lattice parameters a and α were calculated. Both SEM and TEM observations showed a nanometric character of Ni3Sn2S2 prepared films. Optical analysis via the transmittance and reflectance spectra revealed ahigh absorption of this ternary compound in the visible range. A particular behavior of the absorption coefficient was found around 500 nm (green radiation). On the other hand, the absorptivity, which is the meaning of the absorption coefficient pondered on the IAM1.5 solar emission, was also calculated. Basic electric characteristics in terms of electric conductivity at different temperatures were evaluated show a metallic behavior of Ni3Sn2S2 thin film. Finally, the advances in the actively studied electrode that were emerging as effective alternate based cyclic voltammetry were also discussed.

This works deals with the synthesis of Cobalt doped MoO 3 thin films which were grown on glass substrates by the spray pyrolysis at 460 °C. First, X-ray diffraction analysis shows an orthorhombic structure related to α-MoO 3 allotropic variety with (020) and (040) preferred orientations. The surface topography performed by atomic force microscopy (AFM) shows that the grain size varies from 150 to 280 nm. Second, optical parameters, such as optical band gap, Urbach energy, refractive index and dielectric constants were studied in terms of Co content. This optical study shows a direct transition of all prepared thin films and normal dispersion of the refractive index showing both Cauchy and Wemple & Di-dominico variations. On the other hand, PL measurements show transition bands mainly in blue and green domains related to band-to-band transitions as well as to oxygen vacancy in all films. Finally, magnetic measurements at room temperature using vibrating sample magnetometer (VSM) technique reveal a ferromagnetic behavior of such doped films.

This work highlights the wettability properties of La–doped ZnO sprayed thin films deposited on glass substrates at 460 °C in terms of oxygen vacancy induced by this doping element. First, X–ray diffraction (XRD) and scanning electron microscopy (SEM) observations reveal that all films exhibit vertically aligned ZnO nanorods crystallized in wurtzite ZnO phase and the crystallites are orientated towards (002) direction parallel to c–axis. Second, the shift of E 2H peak in Raman spectra reinforces the existence of compressive stress in such doped films which is consistent with XRD analysis. The changes in both A 1 (LO) and E 1 (LO) peaks intensities show that the stress induced defects in terms of La doping. Moreover, to correlate between the evolution of oxygen vacancies concentration and the contact angle measurements, PL measurements were carried out at room temperature. Finally, a discussion has been made regarding the switching behaviors of ZnO:La film surfaces between hydrophobic and hydrophilic states showing that the variation of oxygen vacancy concentration leads effectively to a surface chemistry change which plays an important role in the wettability alteration phenomenon.

This work highlights some physical properties on Eu-doped MoO3 thin films produced by spray pyrolysis. In practice an aqueous solution of ammonium Molybdate containing various concentration of Europium (0–2%) is sprayed on a glass substrate heated at 460 °C in air. X-ray diffraction (XRD) and Raman spectroscopy showed that all the produced films crystallized in the orthorhombic α-MoO3 like structure. Parallel to these structural studies, the X-ray Photoelectron Spectroscopy (XPS) spectra of the doped films were recorded and compared to that of their MoO3 parent. All exhibited the signature of Mo6+ and O2− species related to MoO3 phase while only the doped ones evidenced the signal of Eu3+ with a binding energy close to that Eu2O3 oxide. Scanning Electron Microscopy evidenced a dense coral-like surface morphology suggesting the formation of juxtaposed and superposed differently sized plates during the film growth. The optical properties of the films were also investigated. Transmission and reflection measurements were typically performed. They showed a transmission coefficient decrease when Eu doping increased (40–75%), making them more valuable for gas sensing application based on opto-electronic properties changes. Finally, these doped films having large specific surfaces may be of interest for possible sensitivity applications such as photocatalysis, gas sensors.

Nickel oxide thin films were deposited on glass substrates by a simple mini spray technique at 460 °C. Alternatively, some of the obtained films were doped with potassium at the molar rates of: 1, 2 and 3% (K). In addition to the classical structural investigations including XRD, the opto-thermal studies, Raman spectroscopy and photoluminescence measurements were investigated. First, structural study by means of X-ray diffraction shows that all K-doped NiO thin films crystallized in cubic space group with some noticeable changes in terms of [K]/[Ni] ratio. In the same line, Raman spectroscopy reveals the principal NiO vibration’s mode with the shift related to K incorporation in NiO matrix. Second, some optical parameters, such as optical band gap, Urbach energy, refractive indices extinction coefficients and dielectric constant were studied in terms of K doping level. For all NiO:K prepared thin films, PL measurements show three large bands located at 405, 420, 485 and 529 nm. Furthermore, electrical properties were performed using impedance spectroscopy technique in the frequency range 5 Hz–13 MHz at various temperatures. DC conductivity is thermally activated showing a semiconductor behavior of NiO:K sprayed thin films. This study shows that the electrical conductivity is thermally activated. The calculated values of the activation energy show semiconductor behavior of such films. On the other hand AC conductivity is investigated through Jonscher law. The imaginary part of the complex impedance has a maximum whose relaxation frequency increases with temperature according to Arrhenius law.

This work highlights some physical investigations on tin oxide thin films doped with different lanthanum content (ratio La–to-Sn = 0–3%). Such doped thin films have been successfully grown by spray pyrolysis onto glass substrates at 450 °C. X-ray diffraction (XRD) patterns showed that SnO 2 :La thin films were polycrystalline with tetragonal crystal structure. The preferred orientation of crystallites for undoped SnO 2 thin film was along (110) plane, whereas La-doped ones have rather preferential orientations along (200) direction. Although the grain size values exhibited a decreasing tendency with increasing doping content confirming the role of La as a grain growth inhibitor, dislocation density and microstrain values showed an increasing tendency. Also, Raman spectroscopy shows the bands corresponding to the tetragonal structure for the entire range of La doping. The same technique confirms the presence of La 2 O 3 as secondary phase. Moreover, SEM images showed a porous architecture with presence of big clusters with different sizes and shapes resulting from the agglomeration of small grains round shaped. Photoluminescence spectra of SnO 2 :La thin films exhibit a decrease in the emission intensity with La concentration due to the decrease in grain size. Optical transmittance spectra of the films showed high transparency (∼80%) in the visible region. The dispersion of the refractive index is discussed using both Cauchy model and Wemple–Di-Domenico method. The optical band gap values vary slightly with La doping and were found to be around 3.8 eV. It has been found that La doping causes a pronounced decrease in the sheet resistance by up to two orders of magnitude and allows improving the Haacke's figure of merit (Φ) of the sprayed thin films. Moreover, we have introduced for a first time a new figure of merit for qualifying photo-thermal conversion applications. The obtained high conducting and transparent SnO 2 :La thin films are promising to be useful in various optoelectronic applications.

Lanthanum-doped nickel oxide NiO:La thin films were deposited onto glass substrates at 450 °C, by the spray pyrolysis technique using nickel and lanthanum chlorides as precursors. These films belonging to cubic structure, crystallize preferentially along (111) plane. First, Raman study shows the presence of bands corresponding to NiO structure. The same study confirms the presence of both Ni(OH) 2 and LaNiO 3 as secondary phases. Moreover, using SEM observations, all samples exhibit porous microstructures with rough surfaces and spherical nanoparticles of about 40 nm as size. Second, NiO:La films present a direct band gap energy value lying in the range of 3.63–3.84 eV. Also, the effect of the La incorporation in NiO matrix on the disorder is studied in terms of Urbach energy. Some optical constants (refractive index, extinction coefficient, dielectric constants, and dispersion parameters) are reached. On the other hand, the photoluminescence spectroscopy reveals the presence of peaks related to the electronic transition of the Ni 2+ ions and others confirming the presence of some defects in NiO matrix in terms of La content. Finally, it has been found that La doping allows the improvement of the electrical conductivity as well as Haacke’s figure of merit of NiO sprayed thin films by at least, three orders of magnitude.

Europium doped ZnO thin films were deposited on glass substrates using a simple mini spray technique at 460 °C. The structural properties of as-prepared thin films were characterized by X-ray diffraction (XRD). Both undoped and Eu-doped films show strong preferred c -axis orientation. The maximum value of the volume cells was obtained at 1% doping level. The texture coefficient (TC) of the films along (002) direction changes with the doping level due to Eu incorporation. The optical band gap calculated from transmittance and reflectance spectra show the effect of concentration on this energy. They equally outlined the direct gap absorption of these materials. Analysis of Urbach–Martienssen model parameters allows nano-scale explanations of the doping-related divergence of Urbach tailing evolution.

Aluminum oxide (Al 2 O 3 ) ceramics has been prepared by spray pyrolysis technique. X-ray analysis shows that the prepared thin films crystallize in κ-Al 2 O 3 (kappa-alumina) phase with orthorhombic structure. Also, the crystallites are mainly orientated along (201) direction. The dispersion of the refractive index was discussed in terms of single oscillator model proposed by Wemple and Di-Domenico. The single oscillator energy ( E 0 ) as well as the dispersion energy ( E d ) was therefore calculated. Finally electrical properties were performed using impedance spectroscopy technique in the frequency range 5 Hz to 13 MHz at various temperatures (300–400 °C). DC conductivity was thermally activated, showing a semiconductor behavior of κ-Al 2 O 3 sprayed thin films. Elements from the Lattice Compatibility Theory analyses have been also presented in order to give a plausible understanding for the recorded chlorine/oxygen rapid substitution within AlCl 3 lattices. On the other hand AC conductivity was investigated through Jonscher law. The imaginary part of the complex impedance has a maximum whose relaxation frequency increases with temperature according to the Arrhenius law. Values of dielectric constants were calculated.

Oxygen deficient LaMnO3 thin films were successfully grown on glass substrate by spray pyrolysis at 460 °C. XRD studies show oxygen vacancies corresponding to the orthorhombic La4Mn4O11 with (040) preferential orientation. Optical properties were investigated through optical band gap and Urbach energy. The dispersion of the refractive index was discussed in terms of both Cauchy and Wemple & Di-domenico models. Raman spectroscopy shows the band positions corresponding to LaMnO3 with a shift related to oxygen deficiency. Electrical properties were quantified using impedance spectroscopy technique within frequency range of 5 Hz–13 MHz at various temperatures. Both the DC conductivity and relaxation frequency were thermally activated with activation energy around 0.9 eV. Also, AC conductivity was investigated through Jonscher law. Finally, magnetic measurements at room temperature using vibrating sample magnetometer (VSM) technique show ferromagnetic behavior of these ternary sprayed thin films.

In this work, perovskite La1−xNixMnO2.75 (with x = 0, 0.1, 0.2, 0.3 and 0.4) is synthesized by spray pyrolysis route at 460 °C. X-ray pattern analysis showed orthorhombic structure of the pure and Ni-doped. Based on X-ray analysis interesting parameters are then extracted such as crystallite size, micro-strain ( e ) and dislocation density ( δ ). A high transmittance coefficient at 76 % and the optical band gap varies from 2.33 to 2.85 eV are revealed by the spectroscopy analysis. The Urbach energy varies from 273 to 381.7 meV. Furthermore, refractive index, extinction coefficient, and dielectric constants versus photon wavelength are plotted for pure and Ni-doped LaMnO2.75 layers. PL measurements analysis describe peaks within violet, blue, and green emission ranges. Finally, Doppler-broadening energy studies have been performed to investigate the defect structural evolution in polycrystalline La1−xNixMnO2.75. The studies derived S, R and W parameters are used to perovskite samples.

(Bi2S3)x (γ-MnS)1-x composite thin films have been deposited onto glass substrates using spray pyrolysis method. The structural and compositional investigations confirmed the co-existence of Bi2S3 and γ-MnS binary compounds in the thin films. The surface morphology indicated that the increase in Bi2S3 concentration influences both the shape and the size of γ-MnS crystallites. The optical analysis via transmittance and reflectance measurements revealed that the band gap energy Eg decreased from 3.29 eV to 1.5 eV in terms of Bi2S3 content. The electrical parameters such as resistivity ρ, mobility μ, carrier concentrations and Hall coefficient have been obtained by Hall Effect measurements. It is found than incorporation of Bi2S3 enhances the conductivity, and p-type conduction of γ-MnS could be converted to n-type at x = 0.5. The vibrating sample magnetometer measurement has revealed that (Bi2S3)x (γ-MnS)1-x composite thin films have a ferromagnetic behavior at room temperature.

In2O3 : Eu thin films were successfully grown by spray pyrolysis. XRD studies showed that the films had In2O3 cubic structure with (004) preferential orientation and best crystal properties at 1.5% Eu doping level. The optical band gap energy decreased with Eu content around 4.1 eV. Urbach energy was of the order of 278 meV, it decreased with Eu content which indicates a decrease in the defects by doping. The dispersion of the refractive index was discussed. Raman spectroscopy showed the band positions corresponding to In2O3 cubic phase with a small shift related to europium incorporation within In2O3 matrix. PL measurements showed a large band which was located at 410 nm and related to the band-to-band transitions and other bands related to impurity levels. Finally, the electric conductivity was investigated depending on the effect of temperature. Activation energy was found to range from 45 to 60 meV for films which were prepared with 1% Eu content.

In this work, structural, electrical properties of Li doped ZnO thin films, by chemical pulverization grown on glass substrates at different Li doping concentrations, were reported. Besides, The effects of lithium doping on structural properties of ZnO: Li thin films were studied by means of XRD technique. This study demonstrated that all prepared thin films consisted of unique phase ZnO and were well crystallized in wurtzite structure with the preferentially orientation (002) in the direction parallel to c-axis. The obtained results showed that these films have polycrystalline wurtzite-structure and high c-axis preferred orientation. Besides, the ZnO photodetectors revealed superior performance in the view of photocurrent.

In this study, the preparation of the zinc sulfide thin film by a substitution oxygen-sulfur inside sprayed ZnO compounds are investigated. First, the spray pyrolysis method has been used to grow the ZnO layers on glass substrates at 450 °C. The annealing process time was 12 hours. After a suitable cooling phase, the whole substrate-layer was introduced into a sealed tube. Consecutively, sulfur powder was introduced and vaporized under vacuum conditions inside the sealed tube containing the formerly ZnO prepared thin film. The structural properties of the prepared samples were characterized by X-ray diffraction (XRD) technique. We found that ZnS thin film have the cubic structure with a preferred orientation along (111) plane without any impurities and secondary phases. UV-VIS measurements show that the average transmittance of the ZnS thin films is between 63 and 73%. The optical band gaps for the ZnS and ZnO thin films were estimate too and it was 3.67 – 3.28 eV respectively.