Low Cost Spray Pyrolysis Technique Research Articles

Synthesis and properties of alkaline earth elements (Ca, Sr, and Ba) doped SnO2 thin films

Transparent conductive oxides (TCOs) are commonly used in many optoelectronic, photovoltaic, and catalytic applications because of their unique optical transparency and electrical conductivity. In this work, we report, for the first time, on the optical and electrical properties of Ca-doped tin thin films, and we shed more light on the structure and properties of Sr- and Ba-doped SnO2 thin films. A simple and low-cost spray pyrolysis technique (SPT) was used to synthesize SnO2 thin films doped with alkaline earth elements (Ca, Sr, and Ba) that have ionic radii larger than tin ion radius. The microstructural features of the prepared samples were investigated using a scanning electron microscope, an atomic force microscope, and an x-ray diffractometer. The presence of the dopants and relevant chemical bonds were ascertained through Fourier Transform-Infrared (FT-IR) spectroscopy. The optical and electrical properties were characterized using a spectrophotometer and a four-point probe analyzer, respectively. The synthesized thin films were polycrystalline and had a tetragonal rutile structure with preferred growth orientation along <110> direction. Doping with Ca increased the crystallite size and decreased the dislocation density and micro strain, whereas opposite trend was observed for samples doped with Sr and Ba. The films had smooth, dense, continuous, and homogenous surface. FT-IR analysis revealed the presence of O–Sn–O, Ca–O–Ca, Ba–O and Sr–O bonds. Doping SnO2 with Ca, Sr and Ba improved its optical transmittance from 67% to around 82%. The band gap of pure SnO2 (3.57 eV) decreased to 3.08 and 3.05 eV as a result of doping with Ca and Sr, respectively; and increased to 3.60 eV because of doping with Ba. Strontium and calcium increased the electrical conductivity of SnO2 from 5.79 (Ω cm)−1 to 36.24 and 56.11 (Ω cm)−1, respectively; but barium decreased it to 2.45 (Ω cm)−1. The relatively wide energy gap, high electrical conductivity, and high transmittance of the Ca- and Sr-doped films make them good candidates in diverse functional applications.

Ultraviolet photoconductivity and photoluminescence properties of spray pyrolyzed ZnO nanostructure: Effect of deposition temperature

The current investigation focuses on the influence of substrate temperature on Zinc Oxide (ZnO) thin films synthesized on glass substrates using 0.1 M precursor solution by low-cost spray pyrolysis technique. The x-ray diffraction peaks matched the hexagonal wurtzite structure of ZnO with the highest intensity along the (1 0 1) plane. Estimated the crystallite size, dislocation density, micro-strain, and the number of crystallites in the deposits using X ray diffraction (XRD) data. The crystallinity of the films deposited at 450 °C was maximum. Fibrous surface morphology is altered by varying the deposition temperature. The enhancement of optical transmittance and energy bandgap of the deposits with deposition temperature. The reduction of Urbach energy with an increase in the substrate temperature confirmed the improvement of crystallinity. The photoluminescence study revealed peaks associated with electron-hole pair recombination, zinc, and oxygen-related defects. The samples deposited at 450 °C showed minimum defects. Commission Internationale de l'éclairage (CIE) chromaticity diagram showed white light emission for sample deposited at 450 °C with the color temperature equal to 5378 °C which is agreeing with the temperature of a normal white light source. Improvement of free carrier concentration and n-type conductivity due to the enhancement of crystallinity was observed. ZnO thin films deposited at 450 °C showed maximum photocurrent when illuminated with UV light and faster rise and fall of photo resistance due to the improvement in the crystallinity and carrier concentration. The maximum photosensitivity was observed for the samples synthesized at 450 °C. Hence the ZnO thin films deposited at 450 °C can be used as ultraviolet photodetector material.

Synthesis of spray deposited transition metals doped (Cr, Mn, Fe, Ni, and Cu) compositionally complex ZnO thin films with enhanced band gap and magnetism

Compositionally complex ceramics (CCCs) is now considered as a subgroup of high entropy ceramics (HECs); which focuses on the further opportunities of exploring wide compositional spaces and low entropy options of HECs. This study for the first time attempts to render high configurational disorder in the cationic site of ZnO lattice through the incorporation of higher concentration quinary 3d transition metals dopants i.e. Cr, Mn, Fe, Ni, and Cu. The authors here demonstrate the synthesis of pure ZnO and compositionally complex (BaxSrxMnxFexNix) Zn1-5xO (where x = 0.02, 0.04, and 0.06; the samples denoted as 10CCZO, 20CCZO, and 30CCZO respectively) thin films by low-cost spray pyrolysis technique at 250 °C. In order to investigate the unique wurtzite phase stability of all CCZO crystal structures, XRD analyses were carried out with Rietveld refinement. XRD study showed the single hexagonal wurtzite phase presence of P63mc space group in all CCZO samples and notable change in lattice parameters with doping increment. SEM results revealed a significant change in surface morphology as it transformed flake-shaped grains for pure ZnO to flower and interconnected flake patterns. UV–visible spectroscopy disclosed enhanced transmittance and optical band gap of 3.94, 3.97 eV in 10CCZO and 20CCZO, respectively. VSM test showed that the magnetization values increased substantially in CCZO thin films indicating the potential prospect of these CCZO in magneto-optical applications. In addition, tuned functional properties were correlated with microstructural features.

Growth of Co-doped ZnO thin films exhibiting room temperature ferromagnetism using a low-cost spray pyrolysis technique

Growth of Co-doped ZnO thin films exhibiting room temperature ferromagnetism using a low-cost spray pyrolysis technique

Evaluation of spray pyrolysed In:ZnO nanostructures for CO gas sensing at low concentration

Herein, we report the role of indium (In) on the carbon monoxide sensing of ZnO thin films using a low-cost spray pyrolysis technique. The decrease in crystalline size was observed from XRD studies and hexagonal wurtzite structure was confirmed. Photoluminescence and XPS studies proved the presence of various defects in the films. The gas-sensing properties of films toward carbon monoxide (CO) gas indicate that 15 wt% of In in ZnO thin films (IZO) exhibit high response (1.84) to a low concentration of the gas (1 ppm) at 300 °C compared to undoped ZnO (0.53). The observed high response of 15 wt% IZO can be mainly endorsed to the oxygen vacancy defects as observed from the photoluminescence and XPS analysis. Further, the high response is complemented by high surface area and smaller grain size (~ 13.1 nm) with well-defined grain boundaries as evident from SEM analysis as well as XRD studies.

Bandgap tuning in ZnO thin films and enhanced n-type properties through Mn doping synthesized by a simple spray pyrolysis

Undoped and manganese (Mn)-doped zinc oxide (ZnO) thin films have been deposited onto glass substrates at 300[Formula: see text]C using a low cost spray pyrolysis technique. Structural, optical and electrical properties of the as-deposited films have been investigated. Scanning electron microscopy images show the existence of clusters with well-defined nucleation centers consisting of highly dense ganglia-like fibers over a large area around the nucleation center. Chemical compositions of the ZnO and Mn-doped ZnO thin films are studied by using energy dispersive X-ray (EDX) analysis. X-ray diffraction spectra depict that the films have polycrystalline wurtzite structure. The average crystallite sizes are calculated in the range of 8–16 nm by Williamson–Hall method and found in good agreement with Scherer method. Optical transmittance of the films is about 80% in the visible region. Bandgap energy is tuned to 2.83 eV from 3.10 eV with increasing Mn doping. Electrical resistivity at room-temperature decreases significantly with increasing Mn doping as well as increasing temperature from 300–440 K. The activation energies in the temperature ranges 300–350 K and 350–440 K are found to be in the range of 0.25–0.16 eV and 0.35–0.59 eV, respectively. Hall Effect measurements show that the thin films have negative Hall co-efficient indicating [Formula: see text]-type conductivity at room-temperature. Carrier concentration is found to be of the order of 10[Formula: see text] cm[Formula: see text].

Investigations on effect of Eu3+ doping on structural, morphological and nonlinear optical features of chemically grown tin oxide nanostructures

We report the effect of europium doping on the structural, optical and nonlinear optical properties of SnO2 thin films. The undoped and europium doped films (Eu: SnO2) at various concentrations (1 wt%, 3 wt% and 5 wt%) were synthesized via low-cost spray pyrolysis technique. X-ray diffraction (XRD) studies confirmed tetragonal rutile structure of both undoped and Eu: SnO2 thin films. An additional XRD peak at 31.6° was observed for 5 wt% Eu: SnO2 thin films due to the formation of Eu2O3 crystalline phase. The optical transmittance of Eu: SnO2 thin film has increased from 60% to 85% in visible region upon increasing europium concentration. The bandgap of Eu: SnO2 films was observed to be ~ 3.9 eV which further shows a nominal variation upon Eu doping. The PL spectroscopy studies shows emission peak along UV and red region corresponding to Near Band Edge (NBE) emission and oxygen vacancy defects incorporated in the films. The films exhibited good nonlinear optical properties upon europium doping indicating the applicability of grown films in future photonic devices.

Structural, Morphological and Optical Properties of Spray Deposited Multi-doped (Ba, Sr, Mn, Fe and Ni) Compositionally Complex ZnO Thin Films

Configurational disorder due to high level multi element doping has gained huge attention from research community because of its possibility of unique phase stability as well as unusual functional properties. Based on this context extensive researches performed in recent decades to establish a new horizon of materials i.e. high entropy alloy and ceramics. Of-late, compositionally complex ceramics (CCCs) has been released as an extended form of high entropy ceramics (HECs) where compositional space has been broadened by consideration of both non-equimolecular compositions and relatively low entropy regions. This report aims to stabilize ZnO wurtzite phase at room temperature replacing the Zn-site with five metallic elements i.e. Ba, Sr, Mn, Fe, Ni in equimolecular ratio to impose configurational disorder in the ZnO lattice. Therefore, (BaxSrxMnxFexNix) Zn1-5xO (where x=0, 0.01, 0.02 and 0.03; the films are denoted hereby as ZO, 5DZO, 10DZO and 15DZO respectively) thin films were deposited by low cost spray pyrolysis technique at 200°C. These high-level multi-element doping results in significant effects on the structural, morphological, optical properties of pure ZnO thin film. X-ray diffraction study demonstrated ZnO wurtzite phase stabilization for each deposited film. SEM micrographs revealed a noteworthy transition from original nanorod to well distributed homogeneous fine particles morphology. UV-vis spectroscopy disclosed a sharp rise in transparency (~98%) and band gap (4eV) doped films. At the end, correlations of structural and morphological parameters with tuned functional properties were demonstrated.

Smooth growth, characterization and optical properties of Cu2SnS3 thin film via spray pyrolysis method

Simple, low cost spray pyrolysis technique is implemented herein to deposit thin film of Cu2SnS3 on a glass substrate for photovoltaic applications. Structural, physical, chemical and optical properties of the thin film were analyzed by XRD, SEM, AFM and UV-VIS spectroscopy. The XRD pattern indicated tetragonal phase of the deposited Cu2SnS3 thin film having major XRD peaks at 2θ of 28.54°, 33.07° and 47.47° corresponding to the (112), (200), and (220) planes. It was inferred from SEM and AFM micrographs that the surface was smooth without any pinholes or cracks. The root mean square value of film surface roughness was found to be 11.74 nm and film thickness was measured 200 nm. The AFM and SEM results indicated that the deposited thin film was densely packed and strongly adhered to the substrate. The energy band gap of the deposited Cu2SnS3 thin film was found to be 1.6eV via UV–Vis spectroscopy.

Impact of Se doping on optical and third-order nonlinear optical properties of spray pyrolysis fabricated CdS thin films for optoelectronics

Cadmium sulphide is known to have tremendous applications towards optoelectronic and nonlinear devices. Hence, here we have facilely casted the CdS films with diverse Se contents through low-cost spray pyrolysis technique. XRD study defends mono-phase formation of CdS having hexagonal system at all Se doping contents. Scherrer equation was employed to evaluate crystallite size in range of 15–25 nm. Vibrational study reveals the presence of fundamental modes of vibration of hexagonal CdS. EDX and SEM mapping studies approve the existence of Se and its homogeneous distribution all over the film. SEM micrographs shows the nanoscale grains formation on film surface and the size is increasing with Se doping. Optical study revealed that the grown films are of optimal quality with transparency in range of 60–75% with low absorbance and reflectance values. The refractive index values are noted to varied from 1 to 2.7 with wavelength and noticed to be reduced on Se content in UV–Vis region. The reduction in direct and indirect energy gap was found from 2.46 to 2.34 eV and 2.21 to 1.96 eV, correspondingly due to Se. PL emission profile contains an emission band at 528, 529, 529, 530 and 546 nm for 0.0, 0.5, 1.0, 2.5, 5.0 wt% Se:CdS films. Dielectric constant and loss were estimated. The nonlinear refraction (n2) and absorption coefficient (β) and third-order nonlinear susceptibility $$(\chi^{3} )$$ values were determined using Z-scan and observed in order of 10–8 cm2/W, 10–4 cm/W and 10–3 esu, correspondingly. The high values of $$\chi^{3}$$ propose the films for nonlinear applications.

Fabrication of Illumination-Dependent Cu/p-Si Schottky Barrier Diodes by Sandwiching MoO3 Nanoplates as an Interfacial Layer via JNSP Technique

Highly oriented ultrathin MoO3 nanoplate thin films have been synthesized on a large scale using a low-cost spray pyrolysis technique at different substrate temperatures (350°C, 400°C, 450°C, and 500°C). High-quality single-phase orthorhombic α-MoO3 nanoplate film was observed by x-ray diffraction analysis. The surface morphology of the coated films was analyzed by field-emission scanning electron microscopy, revealing two different surface structures, viz. nanorods and nanoplates. Under atomic force microscopy, the surface roughness of the films was found to decrease with increasing substrate temperature. The optical properties of the α-MoO3 nanoplate thin films were analyzed by ultraviolet–visible and photoluminescence spectroscopy. The optical bandgap varied from 2.8 eV to 3.2 eV, recording a red-shift in the emission, with increasing substrate temperature from 350°C to 500°C. The electrical conductivity was also found to increase linearly with increasing substrate temperature. Various photodiode parameters such as ideality factor (n), barrier hight (ФB), photo sensitivity (PS), resistivity (R), quantum efficiency (QE) and detectivity (D*) were calculated for different light intensities from 0 mW/cm2 to 120 mW/cm2 based on the I–V characteristic. The diode fabricated at 500°C showed a remarkably high photosensitivity and specific detectivity of 610.51% and 1.149 × 1011 Jones when measured at 120 mW/cm2.

Precursor nature and molarities effect on the optical, structural, morphological, and electrical properties of TiO2 thin films deposited by spray pyrolysis

Titanium oxide thin films were deposited by a simple and low-cost spray pyrolysis technique using two different precursors: Titanium chloride (TiCl3) and Titanium Tetra-isopropoxide (TTIP) on glass substrates. X-ray diffraction shows that most of the TiO2 thin films are amorphous in structure. The optical transmittance of the sprayed TiO2 films deposited from Titanium chloride is in the range of 80 % and for the films deposited from TTIP, it attains 90 % in the visible region. The optical band gap energies of the films deposited from TiCl3 and TTIP are about 3.5 and 3.7 eV respectively. The electrical resistivity of the films varies from 3.2*103 to 4.6*104 (Ω.cm) for the films prepared from TiCl3 precursor and 9.4*102 to 6.5*103(Ω.cm) for the films prepared from TTIP precursor.

A study of 8 MeV e-beam on localized defect states in ZnO nanostructures and its role on photoluminescence and third harmonic generation

In this article we have explored an effect of electron beam irradiation (EBI) on physical and nonlinear optical properties ZnO thin nano films. Nanostructured ZnO thin films were grown by low cost spray pyrolysis technique. The irradiation dosage has been fixed at 5 kGy, 10kGY, 15 kGy and 20 kGy. The structural investigation by Glancing angle X-Ray Diffractometer (GAXRD) confirms a polycrystalline phase of ZnO with wurtzite structure. The variation in the surface morphology upon EBI has been demonstrated using 2D and 3D Atomic force microscopy (AFM) images. Nanoscope software analysis quantifies the variation in surface roughness and average particle height upon EBI. The defect states created in the films upon irradiation experiments were investigated using UV–visible spectrophotometer, Room temperature Photoluminescence (RTPL), Raman and X-ray photoelectron spectroscopy (XPS). The increase in urbach tail validates the creation of localized defect states in the films The Gaussian fitting on RTPL spectra shows the quenching in the luminescent centers upon irradiation arised as result of recombination of vacancy defects. Phonon confinement model fitting on Raman spectra endorses that shift in the phonon modes observed on irradiation is due to spatial confinement of phonons. The elemental composition and impurity states of the EBI ZnO thin films were studied using XPS spectra. The shift in the binding energy of Zn and O elements infers the electron beam induced changes in the films. The electron beam irradiation has resulted in the increment of third order optical susceptibility χ(3) 3.5 × 10−4 esu to 8.13 × 10−3 esu due to the enhancement of electronic transition to different defect levels formed in the films and through local heating effects arising due to continuous wave (CW) laser illumination. The enhanced THG signal investigated using Nd:YAG laser at 1064 nm and 8 ns pulse width shows the promising features of EBI ZnO films for frequency tripling applications.

Effect of vanadium doping on ZnO sensing properties synthesized by spray pyrolysis

Semiconductor oxides with high sensing capacity remain a real challenge from long ago. Several attempts were considered to enhance the sensor's performance factors and achieve high quality requirements. In the present work, we operated a chemical sensor using intrinsic and vanadium doped zinc oxide. These samples were prepared and deposited using low cost spray pyrolysis technique. The structural data revealed good surface morphology and roughness, confirming the existence of ideal environment for oxidizing/reduction reactions. The addition of 4% vanadium minimized the grain size with a diameter lower than 9nm. The gas testing measurements showed that vanadium doped ZnO presented higher response compared to pure ZnO. V-doped ZnO confirmed an improvement of the optimal operating temperature which varies from 350°C to 300°C at 100ppm of acetone, 50ppm of ethanol and 500ppm of H2. Furthermore, V-doped ZnO showed a maximum response reaching 100 at 100ppm, for 450°C. This high response is attributed to the effect of vanadium impurities that altered ZnO structure which was confirmed by structural data.

Plasmonic metamaterial-based chemical converted graphene/TiO2/Ag thin films by a simple spray pyrolysis technique

Graphene based hybrid nanostructures have received special attention in both the scientific and technological development due to their unique physicochemical behavior, which make them attractive in various applications such as, batteries, supercapacitors, fuel cells, solar cells, photovoltaic devices and bio-sensors. In the present study, the role of plasmonic metamaterials in light trapping photovoltaics for inorganic semiconducting materials by a simple and low cost spray pyrolysis technique has been studied. The plasmonic metamaterials thin film has been fabricated by depositing chemically converted graphene (CCG) onto TiO2-Ag nanoparticles which has a low resistivity and a low electron–hole recombination probability. The localized surface plasmon resonance at the metal-dielectric interface for the Ag nanoparticles has been observed at 403nm after depositing chemical converted graphene (CCG) on the TiO2-Ag thin film. The results suggest that the stacking order of the CCG/TiO2/Ag plasmonic metamaterials samples did not change the band gap of TiO2 while it changed the conductivity of the film. Thus the diffusion of the noble metals in the glass and TiO2 matrices based thin films can trap the light of a particular wavelength by mean of plasmonic resonance and may be useful for superior photovoltaic and optoelectronic applications.

Effect of precursor solutions on the structural and optical properties of sprayed NiO thin films

Nickel oxide thin films were deposited by a simple and low-cost spray pyrolysis technique using three different precursors: nickel nitrate, nickel chloride, and nickel acetate on corning glass substrates. X-ray diffraction show that the NiO films are polycrystalline and have a cubic crystal structure, although predominantly with a preferred 111-orientation in the growth direction and a random in-plane orientation. The deconvolution of the Ni 2p and O 1s core level X-ray photoelectron-spectra of nickel oxides produced by using different precursors indicates a shift of the binding energies. The sprayed NiO deposited from nickel nitrate has an optical transmittance in the range of 60–65% in the visible region. The optical band gap energies of the sprayed NiO films deposited from nickel nitrate, nickel chloride and nickel acetate are 3.5, 3.2 and 3.43eV respectively. Also, the extinction coefficient and refractive index of NiO films have been calculated from transmittance and reflectance measurements. The average value of refractive index for sprayed films by nickel nitrate, nickel chloride and nickel acetate are 2.1, 1.6 and 1.85 respectively. It is revealed that the band gap and refractive index of NiO films by using nickel nitrate corresponds to the commonly reported values. We attribute the observed behavior in the optical band gap and optical constants as due to the change of the Ni/O ratio.

Photovoltaic effect in earth abundant solution processed Cu2MnSnS4 and Cu2MnSn(S,Se)4 thin films

In this work, we present the first report on thin film solar cells that employ Cu2MnSnS4 (CMTS) and Cu2MnSn(S, Se)4 (CMTSSe) as the absorber. CMTS and CMTSSe thin films are fabricated using a low cost spray pyrolysis technique in ambient atmosphere using water as a solvent. The crystal structure of the materials are similar to the established kesterite type photovoltaic materials such as Cu2ZnSn(S, Se)4 (CZTSSe). The bandgap of these materials is between 1.4−1.7eV, which is ideal for optimum solar absorption and can be tuned by varying the ratio of the elemental constituents. The photovoltaic device with a structure of Mo/CMTS/CdS/TCO/top electrode is fabricated as a proof-of-concept and yields a power conversion efficiency of ~0.73% for the best optimized CMTS device with Na doping. Through analysis of the device characteristics, we identify a key problem of very high carrier density in the CMTS/CMTSSe absorber that leads to short collection length, low Voc, low quantum efficiency at long wavelength and high shunt conductance that quench the fill factor. We also discuss several routes to improve the device performance.

Fabrication and properties of samarium doped calcium sulphate thin films using spray pyrolysis technique

Using low cost spray pyrolysis technique, polycrystalline CaSO4 thin films were successfully grown on a glass substrate with a thickness of about 1 μm. Samarium doping has been performed on CaSO4 thin films to explore luminescence properties. The characterizations of these films were carried out using X-ray diffraction, Scanning Electron Microscopy and optical measurements. The structural analyses reveal the existence of hexagonal CaSO4 phase with a (200) preferred orientation belonging to CaS compound for substrate temperatures below 350 °C. It is shown that the crystallinity of the sprayed thin films can be improved by increasing substrate temperature up to 250 °C. Warren-Averbach analysis has been applied on X-ray diffractogram to determine structural parameters involving the phase with its amount, the grain size and the lattice parameters using Maud software. The surface topography shows a rough surface covered by densely packed agglomerated clusters having faceted and hexagonal shapes. Energy dispersive microscopy measurements confirm the presence of calcium and sulfur in equal proportions as well as high percentage of oxygen. Photoluminescence at room temperature revealed that luminescence peaks are attributed to the intrinsic emission of pure CaSO4 phase.

Preparation and characterization of MgS thin films using spray pyrolysis technique

MgS thin films have been successfully prepared using low cost spray pyrolysis technique. Magnesium sulphate (MgSO4·7H2O) was the source of Mg2+ while sodium thiosulphate served as the source of S2−. Ethylene diamine tetra acetic acid (EDTA) was used to slow down the reaction rate. The aim of this study is to establish the optimized experimental conditions needed to grown MgS thin films. X ray diffraction and atomic force microscopy (AFM) techniques are used to examine the effect of the concentration of the agent complexant EDTA used to grow MgS thin films. The structural analysis shows the formation of MgS thin film with preferential orientation (200) for sprayed solution containing EDTA. It is revealed also the diffraction peaks belonging to the MgSO4 thin films crystallizing in orthorhombic structure. All samples were well adhered to the substrate as revealed from AFM images. The optical properties of MgS thin films were investigated using spectrophotometric measurements in the wavelength range 250–2500 nm. These films, because of their low reflectance and high transmittance in the infrared regions, are suitable for coatings on different types of solar collectors.

Raman spectroscopy of Cu-Sn-S ternary compound thin films prepared by the low-cost spray-pyrolysis technique.

Cu-Sn-S (CTS) thin films were deposited onto bare and molybdenum (Mo) coated glass substrates by means of the spray pyrolysis technique under different conditions. The CTS thin films obtained are shown, by means of Raman spectroscopy, to consist of two main phases: Cu2SnS3 and Cu3SnS4 as well as of the secondary phase of Cu2-xS. The electrical conductivity of the spray-deposited p-type CTS thin films under investigation is determined by two shallow acceptor levels: Ev+0.07 eV at T<334 K and Ev+0.1 eV at T>334 K. The material of the CTS thin films was established to be a direct-band semiconductor with the bandgap Eg=1.89 eV. The SEM and x-ray energy dispersive analysis show the surface and cross section of the CTS thin film deposited onto molybdenum-coated glass ceramics substrate with the actual atomic ratios of Cu:Sn:S being 2.9:1:2.64, which is in good agreement with the Raman spectra. Also, a small content of residual Cl atoms was found in the CTS thin films under investigation as the by-product of the pyrolytic reactions.