SnS Thin Films Research Articles

Development of SnS (FTO/CdS/SnS) thin films by nebulizer spray pyrolysis (NSP) for solar cell applications

Herein we report a well-organized analysis on various key-properties of SnS thin films for solar cell fabricated by nebulizer spray pyrolysis technique. X-ray diffraction study reveals the polycrystalline nature of deposited films with orthorhombic crystal structure. The crystallite size was calculated and observed to be in the range of 8–28 nm with increasing molarity of precursor solution. The stoichiometry composition of SnS was confirmed by EDX study. SEM/AFM studies divulge the well-covered deposited surface with spherical grains and the size of grains is increasing with concentration and so the roughness. A remarkable decrease in band gap from 2.6 eV to 1.6 eV was noticed by raising the molar concentration from 0.025 M up to 0.075 M. A single strong emission peak at about 825 nm is observed in PL spectra with enhanced intensity which may be attributed to near band edge emission. From the Hall effect measurement, it was found that the SnS thin film exhibits p-type conductivity. The calculated values of resistivity and carrier concentration are 0.729 Ω cm and 3.67 × 1018/cm3 respectively. Furthermore, to study the photovoltaic properties of SnS thin films a heterojunction solar cell, FTO/n-CdS/p-SnS was produced and the conversion efficiency was recorded about 0.01%.

Synthesis of SnS Thin Films by Atomic Layer Deposition at Low Temperatures

Two-dimensional (2-D) metal chalcogenides have received great attention because of their unique properties, which are different from bulk materials. A challenge in implementing 2-D metal chalcogenides in emerging devices is to prepare a well-crystallized layer over large areas at temperatures compatible with current fabrication processes. Tin monosulfide, a p-type layered semiconductor with a high hole mobility, is a promising candidate for realizing large-area growth at low temperatures because of its low melting point. However, tin sulfides exist in two notable crystalline phases, SnS and SnS2. Therefore, it is imperative to control the oxidation state of Sn to achieve a pure SnS film. Here, the synthesis of SnS thin films by atomic-layer-deposition (ALD) is demonstrated using bis(1-dimethylamino-2-methyl-2-propoxy)tin(II) and H2S as Sn and S sources, respectively, over a wide temperature window (90–240 °C). Impurities such as carbon, oxygen, and nitrogen were negligibly detected. The morphological evol...

Deposition of SnS Thin Films from Sn(II) Thioamidate Precursors

Two thioamide pro-ligands, R1N(H)C(=S)R2 (R1 = t-Bu, R2 = i-Pr and R1 = i-Pr, R2 = i-Pr), were synthesized by treatment of the corresponding amides with Lawesson’s reagent. Reactions of [Sn{N(SiMe3)2}2] with two molar equivalents of each thioamide pro-ligand yielded the tin(II) thioamidate species, bis(2-methyl-N-(1-methylethyl)-propanethioamide)tin(II) and bis[N-(1,1-dimethylethyl)-2-methyl-propanethioamide]tin(II). Both of the new tin compounds have been characterised by 1H, 1C and 119Sn NMR spectroscopy and elemental analysis. In addition, the solid-state structure of bis(2-methyl-N-(1-methylethyl)-propanethioamide)tin(II) has been determined through a single crystal X-ray diffraction analysis and shown to display a monomeric constitution in which the tin(II) centre occupies a distorted pseudo-square pyramidal geometry defined by the N2S2 donors and the stereochemically active lone pair. Both tin(II) derivatives have been assessed for their potential as single source precursors to SnS by TGA and by NMR...

Effect of sulfur concentration on the properties of tin disulfide thin films by nebulizer spray pyrolysis technique

Influence of sulfur concentration variation on the physical and chemical properties of nebulizer spray pyrolysis deposited SnS2 thin films are investigated. The SnS2 thin films were coated onto glass substrate at 325 °C by changing sulfur concentration as 0.8, 0.9 and 1.0 M. Sulfur concentration dependent micro-structural, surface morphological, optical and electrical characteristics of the films were studied using X-ray diffraction, Raman analysis, scanning electron microscope, atomic force microscope, UV–Vis spectroscopy, photoluminescence spectroscopy and Hall Effect measurement, respectively. X-ray diffraction measurements demonstrated the growth of crystalline SnS2 films of hexagonal structure with preferred orientation along (002) plane. Scanning electron microscopic study revealed needle shape and basket knitting shape morphology of deposited films. The films showed direct band gap ranging from 2.02 to 2.18 eV depending on sulfur concentration. Hall measurement revealed the conductivity and mobility ranging from 10−3 to 10−2 (1/Ω-cm) and 1.4 × 102 to 3.01 × 102 (cm2/V s) respectively.

Preparation of SnS2 thin films by conversion of chemically deposited cubic SnS films into SnS2

We report the growth of SnS2 thin films by annealing chemically deposited cubic SnS films under a sulfur atmosphere in a graphite box. The chemically deposited SnS films were annealed in the temperature range of 200–550°C to understand its influence on the conversion of SnS into SnS2. In the X-ray diffraction analysis, the as-deposited SnS films annealed in the temperature range of 200–250°C showed the formation of a minor SnS2 phase along with the dominant SnS phase. The films annealed at 300°C contained mixed phases of SnS and SnS2. Increasing the annealing temperature from 350 to 500°C led to the formation of only the dominant SnS2 phase. Further increasing the annealing temperature to 550°C gave rise to the formation of a highly oriented SnS2 film with hexagonal structure having (001) as the preferred orientation. The crystallite size of the SnS2 films was found to increase from 17nm to 25nm with increasing annealing temperature from 350°C to 550°C. The lattice parameters were found to be a=0.365nm and c=0.592nm. Raman spectroscopy analysis confirmed the formation of single phase SnS2 films at annealing temperatures above 350°C. The morphological studies showed the conversion of the round shaped grains into flake-like ones on annealing at temperatures above 350°C. These flakes increased in size on increasing the annealing temperature from 350°C to 500°C. The direct optical band gap of these SnS2 films was found to be 2.58eV.

Pulse Electrodeposition Synthesis and Characterization of Sns Thin Films Obtained from Dimethyl Sulfoxide Solutions

Thin film materials for solar photovoltaic energy conversion have been considered a good option to provide a low cost power supply for a progressive increasing demand across the world. The most intensively studied and commercialized thin film solar cells are those based on (CIGS), Cu(In,Ga)Se2 and CdTe. Concerns regarding the cadmium because its toxicity and the limited abundance of indium and gallium could limit the future of these technologies. For these reasons alternative materials to develop new photovoltaic solar cells are currently investigated around the world. From the point of view of earth abundance, cost and toxicity SnS appears as a promising candidate. It has a direct optical band gap value (1.5 eV) which is within the optimum range for photovoltaic solar energy conversion. It exhibits p-type conductivity and high optical absorption coefficient meaning that only some microns of thickness could absorb most of the incident light. Theoretical calculations predict a conversion efficiency of 24% for materials with the same band gap1, however the reported efficiency for solar cells based on SnS is less than 2%2. Such low efficiencies were attributed to factors like poor quality of the films, grain boundaries, lower thickness employed, insufficient diffusion lengths in the layers and large band discontinuities. Hence, in order to obtain better efficiencies in SnS based solar cells the quality of the layers need to be substantially improved. Electrodeposition is one of the economical methods for large surface coating and has been successfully used to prepare semiconductor films. The method allows the control of the bandgap width and the doping level through the control of variables such as solution composition, applied potential, pH and working temperature. Furthermore, monitoring the circulating charge it is also possible to control the thickness of the deposited layers. Metal chalcogenides have been generally electrodeposited by the cathodic co-reduction of the metal and chalcogenide ions. However, compositional heterogeneity is usually a problem with this approach. An attractive option involves the use of aprotic deposition baths such as dimethylsulfoxide which presents a high boiling point and also allows the solubility of the chalcogene precursor in nonionized, molecularly dissolved form. In this solvent it is possible to form binary compounds starting from the electrochemical reduction of the elementary chalcogen precursor and the consecutive formation of a chalcogenide anion that further precipitates heterogeneously onto the surface of a convenient substrate for the formation of II-VI semiconductors. In current work SnS thin films were prepared on molybdenum substrates by pulsed electrodeposition at differents synthesis times. The structure, morphology and composition were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and Raman spectroscopy. The optical and electrical properties were studied by UV–vis absorption and capacitance-potential curves, respectively. The electrodeposited SnS films showed p-type semi-conductive characteristics and exhibited cathodic photocurrent under visible light illumination. Highly compact, dense, homogenous and almost stoichiometric films were obtained by properly selecting the electrodeposition parameters. These results show that the as grown films show composition and thickness compatible with the requirements of SnS based solar cell devices Acknowledgements: ToEuropean Commission, NanoCIS project FP7-PEOPLE-2010-IRSES grant 269279 and to CONICYT (Chile), FONDECYT (Fondo de Desarrollo Cientifico y Tecnológico, Chile) through Project N° 3160217.

Influence of precursor solution volume on the properties of tin disulphide (SnS2) thin films prepared by nebulized spray pyrolysis technique

Tin disulphide (SnS2) thin films have been deposited with various precursor solution volumes (5–25ml) by nebulized spray pyrolysis technique onto glass substrates. The X-ray diffraction studies revealed that the as-deposited SnS2 thin films were polycrystalline in nature and having a hexagonal structure with a single preferential orientation along (001) plane. SEM analysis revealed that all the thin films had platelet-like grains. The EDAX analysis confirmed the presence of tin and sulphur. Multiple interference effect was predominant in all these thin films in the wavelength region of 500–1100nm. Direct band gap values were found to decrease up to 2.67eV with the increase in precursor solution volumes from 5 to 20ml and increased further. All the SnS2 thin films were found to be n-type semiconductors. The better conductivity and mobility noticed at the precursor solution volume of 20ml are explained by carrier concentration and crystallites. The Activation energy of these films was determined by plotting a graph between log (resistivity) versus reciprocal temperature using a four-probe method.

SnSx (x = 1, 2) Nanocrystals as Effective Catalysts for Photoelectrochemical Water Splitting

Two-dimensional SnSx (x = 1, 2) nanocrystals are attractive catalysts for photoelectrochemical water splitting as their components are earth abundant and environmentally friendly. We have fabricated SnS thin-film photoelectrodes by spin coating mixed-phase SnS nanocrystals synthesized via a hot-injection technique on glass/Cr/Au substrates. The obtained SnS thin films can be transformed into SnS2 by introducing structural phase changes via a facile low-vacuum annealing protocol in the presence of sulfur. This sulfurization process enables the insertion of sulfur atoms between layers of SnS and results in the generation of shallow donors that alter the mechanism for water splitting. The SnS2 thin films are used as stable photocatalysts to drive the oxygen evolution reaction, and the light-current density of 0.195 mA/cm2 at 0.8 V vs. Ag/AgCl can be achieved due to the high carrier density, lower charge transfer resistance, and a suitable reaction band position. Based on a combination of UV-Vis spectroscopy (ultraviolet and visible spectroscopy), cyclic voltammetry and Mott–Schottky analysis, the band positions and band gaps of SnS and SnS2 relative to the electrolyte are determined and a detailed mechanism for water splitting is presented. Our results demonstrate the potential of layered tin sulfide compounds as promising photocatalysts for efficient and large-scale water splitting.

Formation of metastable cubic phase in SnS thin films fabricated by thermal evaporation

Metastable cubic SnS phase (π-SnS) is an emerging material having attractive properties for solar cell applications. In this study, we have investigated the thermal evaporation process of SnS with substrate temperatures of 250–350°C, and have observed the formation of π-SnS together with the stable orthorhombic phase (α-SnS) for the first time by using only SnS as a starting material. X-ray diffraction analysis shows that a single-phase α-SnS film is obtained at 350°C, and the fraction of π-SnS increases with decreasing the substrate temperature to 250°C. The grain shape of the SnS film grown at 250°C observed by scanning electron microscopy was more isotropic than 350°C, consistent with the cubic lattice of π-SnS. Electrical characterization by Hall measurement reveals the existence of the maximum point of carrier density as a function of substrate temperature, which is understood by the competition between the increases of crystal defects and the fraction of wider-gap π-SnS than α-SnS with decreasing substrate temperature. The formation of π-SnS brings about lowering of absorption coefficients below the absorption edge of π-SnS, which are analyzed from transmittance and reflectance spectra. The reason of π-SnS formation is discussed by comparing the conditions of film deposition with previous reports.

Impact of vacuum and nitrogen annealing on HVE SnS photoabsorber films

Researchers worldwide focus on new earth abundant and cheap absorber materials for use in thin film solar cells that allow wider use of photovoltaics in energy production. SnS is one of such promising absorber materials that comprises earth abundant elements (Sn, S). We describe here the effect of annealing of high vacuum evaporated (HVE) SnS thin films in vacuum and nitrogen atmosphere with relatively high pressures of nitrogen. SnS thin films with a thickness of 500nm were deposited onto the surface of glass by HVE at a substrate temperature of 300°C. The as-deposited SnS thin films were annealed at 500°C and 550°C for 1h in vacuum as well as in nitrogen with respect to ambient (N2) pressure that varied in the range of 500–2000mbar. We analyze crystalline quality, crystal structure, elemental and phase compositions, and electrical properties of SnS films before and after the annealing process and their changes. Our results show that the use of pressurized inert ambient, such as nitrogen, improves the crystalline quality as well as the electrical properties of SnS thin films. The enhanced growth of crystals and modification of microstructural properties of SnS thin films as a function of annealing conditions (type of ambient, annealing temperature and ambient pressure) are discussed in detail.

Chemical bath deposition of SnS nanosheet thin films for FTO/SnS/CdS/Pt photocathode

SnS nanosheet thin films were prepared by chemical bath deposition in acidic solution, which used tin (II) chloride dihydrate and thioacetamide as precursors of Sn and S, respectively. The influences of pH levels, precursors' mole ratios, deposition times on the physical properties of SnS nanosheet thin films were investigated. The sheet-like morphologies and compositions of as-deposited SnS thin film were characterized by Scanning electron microscope (SEM). X-ray diffraction (XRD), Raman and X-ray photoelectron spectra (XPS) were used to confirm the crystal structures and phase purities of SnS nanosheet thin films. When employed as a photocathode for photo-electrochemical (PEC) solar hydrogen production, the as-deposited SnS nanosheet thin films yielded photocurrent densities of 31.94 μA cm−2 at −0.4 V under illumination of AM 1.5G. After deposition of CdS and Pt layers, the cathodic photocurrent densities of FTO/SnS/CdS/Pt and FTO/annealed SnS/CdS/Pt were improved to 0.572 mA cm−2 and 0.702 mA cm−2, respectively, which demonstrated the great potential of using earth-abundant SnS for efficient hydrogen production.

Preparation of SnS thin films with gear-like sheet appearance by close-spaced vacuum thermal evaporation

SnS thin films with gear-like sheet appearance were successfully prepared by close-spaced vacuum thermal evaporation using SnS powders as a source. The influence of substrate temperature on the surface morphology, chemical composition, crystal structure and optical property of SnS thin films was investigated by scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and ultraviolet–visible–near infrared spectroscopy. The results revealed that serration architecture appeared obviously in the edge of the SnS sheet and the strongest peak at 2[Formula: see text]=31.63[Formula: see text] was broadened and many shoulder peaks were observed with increasing substrate temperature. The atomic ratio of Sn to S increased from 1:1.08 to 1:1.20, the grain size became slightly smaller and the optical absorption edge had a blueshift in the SnS thin film with decreasing substrate temperature.

Influence of Cu doping on physical properties of sol-gel processed SnS thin films

Copper-doped tin sulfide thin films (Cu-SnS) with different Cu doping concentrations were prepared by using the spin coating technique and their structural, electrical, and optical properties were studied. All the prepared films were polycrystalline and exhibited diffraction peaks corresponding to orthorhombic SnS with the preferred (111) orientation. The XRD spectra revealed improvement in the preferential orientation and crystalline quality with up to 4% Cu doping concentration, whereas Cu doping concentrations above 4% deteriorate the preferential orientation and crystalline quality. It has been observed that upon Cu doping the band gap decreased significantly from 1.46eV (pure SnS) to 1.37eV (4% of Cu-doped SnS). Hall measurements revealed the p-type semiconducting nature of the SnS thin films. The observations revealed that doping of SnS with Cu causes a noticeable drop in the room-temperature resistivity value from 105Ω-cm for pure SnS to 103Ω-cm for 4% Cu-doped SnS.

Electrochemical growth of SnS thin film: application to the photocatalytic degradation of rhodamine B under visible light

A facile and template-free wet electrochemical technique was used to deposit SnS on tin substrate. Longer time (>40 min) is required for the formation of the chalcogenide thin films and the potential must be carefully controlled to come out with a rough chemical identification of sulfide deposited at low potential scan. The deposition potential is selected from the cyclic voltammetry to preclude the oxidation of SnS to SnS2. The SnS films are uniform and well adhered to the substrate. They were characterized by X-ray diffraction, UV–Vis spectroscopy and electrochemical impedance spectroscopy (EIS). SnS crystallizes in an orthorhombic symmetry (SG: Pnma) and a crystallite size of 42 nm was obtained. The Mott–Schottky plot exhibited a linear behavior with a negative slope, characteristic of p-type conductivity. Holes density of 9.75 × 1020 cm−3, a flat band potential of 0.56 V SCE and a depletion width of ~38 nm were determined. The valence band was located at (−5.41 eV/0.66 V) and derives mainly from S 2−: 3p while the conduction band (3.8 eV/−0.95 V) was primarily made up of Sn2+: 5p orbital. The EIS spectra measured over the frequency range (3 × 10−3–105 Hz) revealed mainly a bulk contribution. On application, rhodamine B was successfully oxidized on SnS films, 38% of the initial concentration (10 mg L−1) disappeared after 4 h of exposure to solar light (90 mW cm−2).

Study of SnS2 thin film deposited by spin coating technique

Thin film deposition of SnS2 was done by spin coating technique at ambient temperature. Deposition was done for different spin speed and spin time. The film thickness dependence on spin speed and spin time was studied. The spin speed was varied from 1000 rpm to 2000 rpm and spin time from 2 s to 6 s for constant speed of 1000 rpm. The elemental composition and crystal structure along with the phase of the as-deposited thin film was determined by the energy dispersive analysis of x-ray (EDAX) and x-ray diffraction (XRD) techniques respectively. The as-deposited thin film was found to be near stoichiometric and possess hexagonal crystal structure with determined lattice parameters in good agreement with the reported values. The crystallite size calculated from the XRD data using Scherrer’s formula and Hall–Williamson relation came out to be 9.77 nm and 6.49 nm, respectively. The transmission electron microscopy (TEM) study of spin deposited thin films showed the film to be continuous. Surface study of the as-deposited thin film was done by simple optical microscope and scanning electron microscope (SEM). The study showed that the deposited thin film to be flat and uniform without visible cracks and pores. The optical spectroscopy study of the as-deposited thin film showed that the optical bandgap value decreases with increase in film thickness. The d.c. electrical resistivity variation with temperature for spin coating as-deposited SnS2 film showed that the resistivity decreases with increase in temperature corroborating the semiconducting nature. The resistivity variation plot possesses two slopes. The temperature ranges showing two slopes lay between 300 to 383 K and 384 to 423 K having activation energy values for the two temperature ranges as 0.072 eV and 0.633 eV, respectively. The achieved results are deliberated in details.

The formation of α-phase SnS nanostructure from a hybrid, multi-layered S/Sn/S/Sn/S thin films: Phase stability, surface morphology and optical studies

Single phase of SnS thin film was fabricated from S/Sn/S/Sn/S multilayer prepared by using atmospheric pressure and vacuum thermal evaporation methods Glancing angle high vacuum thermal evaporation technique was employed to grow Sn nanorods which facilitated the sulphur diffusion in a faster manner to prepare SnS nanoparticles. The sulphur deposition temperature, sulphur deposition time and tin deposition time were successfully tailored in the synthesis process and stabilized α-phase SnS by probing through confocal micro-Raman spectrometer. X-ray diffraction confirms the formation of SnS crystal structure at sulphur deposition temperature 200°C. The mechanism of formation of highly porous SnS phase with flower like morphology is explained from the morphological analysis of post deposition annealed film. The complete absence of any oxidation state as evident from Raman as well as EDAX analysis confirms that the proposed sulphurization method could be a suitable, simple and cheap technique for the successful sulphurization of metal films. Band gap calculation from Tauc plot showed a direct band gap value of 1.5eV for films with single phase of SnS which can be used as a p-type absorber layer in thin film solar cells. Emission studies showed the energy transitions attributed to band edge transition and due to the presence of intrinsic defects.

Structural, morphological and optical properties of SnS2 thin films by nebulized spray pyrolysis technique

The thin films of Nano crystalline tin disulfide (SnS2) have been prepared by nebulized spray pyrolysis technique (NSP) with different molar concentrations (0.3, 0.4 and 0.5 M). Cleaned glass substrates were used and the substrate temperature was maintained at 300 °C. The films were deposited using tin tetrachloride monohydrate (SnCl4·H2O) and thiourea in de-ionized water and Isopropyl alcohol (1:3 ratio). The prepared films structural, morphological and optical properties were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis spectrophotometer. The structure of the films were found to be face centered cubic with preferential orientation along (002) plane. X-ray line profile analysis was used to evaluate the micro structural parameters such as crystallite size, micro strain, dislocation density and texture coefficient. The average crystallite size values are 60 nm. Morphological results of the SnS2 thin films are small needle shaped particles and the average grain size was 400 nm. The optical studies revealed that the band gap between 2.65 and 2.72 eV and high optical transmittance 98%. EDAX spectrum of tin disulfide result showed some amount of excess tin was present in the sample. This is the method with very low cost of producing tin disulfide (SnS2) thin films, which is very important for many applications in industry.

Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications

Spray pyrolised SnS thin films doped with indium were studied using various optical and electrical techniques. Structural analysis shows that all films crystallise in an orthorhombic structure with (111) as a preferential direction, without secondary phases. The doping of SnS layers with indium results in better morphology with increased grain size. Absorption measurements indicate a dominant direct transition with energy decreasing from around 1.7eV to 1.5eV with increased indium supply. Apart from the direct transition, an indirect one, of energy of around 1.05eV, independent of indium doping, was identified. The photoluminescence study revealed two donors to acceptor transitions between two deep defect levels and one shallower one, with an energy of around 90meV. The observed transitions did not depend significantly on In concentration. The conductivity measurements reveal thermal activation of conductivity with energy decreasing from around 165meV to 145meV with increased In content.

Synthesis of SnS thin films via high vacuum sulfidation of sputtered Sn thin films

In this letter, a new approach for the synthesis of SnS thin films is introduced. In this approach, Sn thin films were first deposited on glass substrates by r.f. magnetron sputtering under forming gas (95% Ar+ %5 H2) atmosphere and post-sulfidation of the sputtered Sn thin films was performed under high vacuum (<10−5Torr). Due to low pressure, complete sulphurisation of Sn thin films via diffusion of evaporated S atoms took place at a relatively lower temperature. For a 400nm Sn thin film, 250°C and 150min were determined as the optimum sulfidation temperature and time to obtain orthorhombic SnS thin film. It has been determined that while short sulfidation time (<120min) leads to residual metallic Sn, high sulfidation temperature (>250°C) induces SnS2 formation.

Crystal Structure, Optical, and Electrical Properties of SnSe and SnS Semiconductor Thin Films Prepared by Vacuum Evaporation Techniques for Solar Cell Applications

Thin films of SnSe and SnS semiconductors had been prepared by vacuum evaporation techniques. All prepared samples were characterized on their structure, optical, and electrical properties in order to know their application in technology. The crystal structure of SnSe and SnS was determined by X-Ray Diffraction (XRD) instrument. The morphology and chemical composition were obtained by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive of X-Ray Analysis (EDAX). The optical property such as band gap was determined by DR-UV-Vis (Diffuse Reflectance-Ultra Violet-Visible) spectroscopy, while the electrical properties were determined by measuring the conductivity by four probes method. The characterization results indicated that both SnSe and SnS thin films were polycrystalline. SnSe crystallized in an orthorhombic crystal system with the lattice parameters of a = 11.47 Å, b = 4.152 Å and c = 4.439 Å, while SnS had an orthorhombic crystal system with lattice parameters of a = 4.317 Å, b = 11.647 Å and c = 3.981 Å. Band gaps (Eg) of SnSe and SnS were 1.63 eV and 1.35 eV, respectively. Chemical compositions of both thin films were non-stoichiometric. Molar ratio of Sn : S was close to ideal which was 1 : 0.96, while molar ratio of Sn : S was 1 : 0.84. The surface morphology described the arrangement of the grains on the surface of the thin film with sizes ranging from 0.2 to 0.5 microns. Color similarity on the surface of the SEM images proved a homogenous thin layer.