SYNTHESIS OF NANOCRYSTALLINE SnS FILMS BY CAPPING WITH PVA USING CBD PROCESS FOR SOLAR CELL APPLICATIONS – A COMPREHENSIVE OPTICAL STUDY (original) (raw)
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IAEME PUBLICATION, 2023
Polyvinyl alcohol (PVA) capped tin monosulphide (SnS) nanocrystalline films have been grown successfully on glass substrates using a simple and low-cost wet chemical process, chemical bath deposition (CBD) at four different PVA concentrations that vary from 0.5 wt % to 2 wt %. XRD study indicated peaks related to SnS phase with (040) as preferred orientation. Various parameters such as average crystallite size, dislocation density lattice strain, and stacking faults were also estimated using XRD spectra. Raman analysis also confirmed the XRD results. The SEM and AFM micrographs exhibited a good morphology for the films deposited at 2 wt % concentration of PVA. FTIR studies revealed the presence of PVA in the films. The optical investigations confirmed the high absorbing nature for the experimental films and also, a blue shift in band gap values with PVA concentration was observed. The estimated band gap values vary from 1.73 eV to 1.55 eV, which might be due to quantum confinement effect. Hall measurement studies showed p-type conductivity for all the grown layers. Also, the variation of electrical resistivity, carrier concentration and mobility were studied with PVA concentration and the results are discussed.
IAEME PUBLICATION, 2023
Polyvinyl alcohol (PVA) capped tin monosulphide (SnS) nanocrystalline films have been successfully deposited on glass substrates via a wet chemical route, chemical bath deposition (CBD) at four different deposition times that vary from 45 min to 90 min. Raman spectra exhibited the peaks related to only SnS phase for the films deposited at a higher deposition time of 90 min. The SEM and AFM micrographs displayed bigger grains with compact surface morphology for the films deposited at 90 min time of deposition. Hall measurement analysis revealed that all the grown layers exhibited the p-type conductivity. Also, the influence of deposition time on the electrical properties such as the electrical resistivity, mobility and carrier concentration of the films was studied and the results are discussed.
Annealing effect on structural and optical constants of SnS thin films for solar cells application
Optik, 2017
In this paper thin films of tin sulfide (SnS) were prepared by thermal evaporation method at room temperature on glass substrate and then annealed at different temperature with the aim of optimizing the structural and optical properties of the material for use in photovoltaic solar cell device. The structure and optical properties of SnS film has been studied in different range of annealing temperature from 100 • C to 400 • C with steps of 100 • C for 1 h. The films were analyzed by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), scanning electron microscope (SEM) and optical absorption spectroscopy. X-ray diffraction studies shows that the structural properties of SnS film has been improved with increasing annealing temperature such that the film exhibits better crystallinity and the grain size has been increased, while film of lower annealing temperature exhibits poor crystalline with amorphous nature. The optical properties of the deposited films have been investigated by using UV-vis spectroscopy in the wavelength range of 300-800 nm. The optical constants such as the refractive index (n), extinction coefficient (k) and optical band gap have been calculated in different annealing temperature. The energy band gap in the range 1.60 eV-2.06 eV has been obtained for a film as-deposited which increases clearly with increasing annealing temperature. The refractive index and extinction coefficient both decrease notably with increasing annealing temperature. The obtained results were discussed can be improved to make suitability of SnS film as an absorber for the fabrication of low-cost and commercially viable solar cells.
Structural and Optical Properties of SnS Thin Films
Journal of Nanotechnology & Advanced Materials, 2014
Thin films of tin sulfide (SnS) were prepared by thermal evaporation technique on glass substrates, with thickness in the range of 100, 200 and 300nm and their physical properties were studied with appropriate techniques. The phase of the synthesized thin films was confirmed by X-ray diffraction analysis. Further, the crystallite size was calculated by Scherer formula and found to increase from 58 to 79 nm with increase of thickness. The obtained results were discussed in view of testing the suitability of SnS film as an absorber for the fabrication of low-cost and non toxic solar cell. For thickness, t=300nm, the films showed orthorhombic OR phase with a strong (111) preferred orientation. The films deposited with thickness < 200nm deviated from stoichiometry and additional phases such as Sn2S3 was found to be present. Optical transmission spectra we rerecorded in the wavelength range 200-1100 nm, and the data was used to calculate absorption coefficient and optical band gap. SnS film grown with 300nm has shown a direct optical band gap of ~1.7 eV, with an absorption coefficient of 105cm-1 above the fundamental absorption edge. These polycrystalline and highly absorbing SnS thin films are suitable for the fabrication of hetero junction solar cells.
Parameters influencing the optical properties of SnS thin films
Journal of Semiconductors, 2013
Tin Sulphide (SnS) thin films have been recognized as a potential candidate for solar cells. Many fabrication techniques have been used to grow SnS thin films. The band-gap, Eg of SnS films as reported in literature, were found to vary from 1.2-2.5 eV depending on the film fabrication technique. The present work reports the structural, compositional, morphological and optical characterization of SnS thin films fabricated by thermal evaporation at room temperature. Results show that for the given fabrication technique/ condition, the band-gap functionally depends on the lattice parameter and grain size. The well-defined
Ife Journal of Science
This study presented deposition of tin sulphide (SnS) thin film using a two-electrode electrochemical cell arrangement. The bath electrolyte comprised tin sulphate (SnSO4 ), hydrated sodium thiosulphate (Na2S2O3∙5H2O) and sulphuric acid (H2SO4 ). The acid was used to adjust the pH of the bath. The deposited film was characterised using Surface Profilometer, X-Ray Diffractometer (XRD), Uv-Visible Spectrophotometer and four point probe technique. Surface profiling revealed that the film is continuous with thickness of about 60 nm. The XRD result showed that the film has orthorhombic crystal structure. Film's crystallite size was estimated as 0.61 nm and interplanar spacing as 0.29 nm. The Uv-visible Spectrophotometer result reveals that, the film has good absorbance but poor reflectance and transmittance in the visible light region. The film has direct allowed transition with energy band gap of 1.69 eV. Values of surface resistivity and conductivity were deduced from data obtained...
The preparation and analysis of morphological, structural, optical, vibrational and compositional properties of tin monosulfide (SnS) thin films deposited on glass substrate by chemical spray pyrolysis is reported. The growth conditions were evaluated to reduce the presence of residual phases different to the SnS orthorhombic phase. X-ray diffraction spectra revealed the poly-crystalline nature of the SnS films with orthorhombic structure and a preferential grain orientation along the (111) direction. At high substrate temperature (450 º C), a crystalline phase corresponding to the Sn 2 S 3 phase was observed. Raman spectroscopy confirmed the dominance of the SnS phase and the presence of an additional Sn 2 S 3 phase. Scanning electron microscopy (SEM) images reveal that the SnS film morphology depends on the substrate temperature. Between 250 º C and 350 º C, SnS films were shaped as rounded grains with some cracks between them, while at substrate temperatures above 400 º C, films were denser and more compact. Energy-dispersive x-ray spectroscopy (EDS) analysis showed that the stoichiometry of sprayed SnS films improved with the increase of substrate temperature and atomic force microscopy micrographs showed films well covered at 350 º C resulting in a rougher and bigger grain size. Optical and electrical measurements showed that the optical bandgap and the resistivity decreased when the substrate temperature increased and smaller values 1.46 eV and 60 Ω cm respectively were attained at 450 º C. These SnS thin films could be used as an absorber layer for the development of tandem solar cell devices due to their high absorbability in the visible region with optimum bandgap energy.
SnS-based thin film solar cells: perspectives over the last 25 years
New types of thin film solar cells made from earth-abundant, non-toxic materials and with adequate physical properties such as band-gap energy, large absorption coefficient and p-type conductivity are needed in order to replace the current technology based on CuInGaSe2 and CdTe absorber materials, which contain scarce and toxic elements. One promising candidate absorber material is tin monosulfide (SnS). The constituent elements of the SnS film are abundant in the earth’s crust, and non-toxic. If this compound is used as the absorber layer in solar cells, high efficient devices should be fabricated with relative low cost technologies. Despite these properties, low efficiency SnS-based solar cells have been reported up to now. In this work, we present a review about the state of the art of SnS films and devices. Finally, an analysis about different factors that are limiting high efficiency solar cells is presented.
Structural and optical properties of Tin sulphide thin films
Nucleation and Atmospheric Aerosols, 2007
Tin antimony sulphide thin films have been synthesized as an absorber layer for solar cells. These films are deposited by vacuum thermal evaporation on glass substrate at a pressure of 10-5 torr. The films are then annealed at different temperatures in argon atmosphere. XRD analysis reveals that both as deposited and annealed films are found to be in polycrystalline phase. The crystallinity of the films is significantly enhanced with increasing annealing temperatures. The quantum efficiency is higher in the visible and near infrared region for the annealed films whereas the quantum efficiency of as deposited film is comparatively lower. The transmittance of the annealed films is found to be decreasing with increasing temperatures. The thickness and band gap of the films are measured by ellipsometric data. The absorption coefficient of the films is significantly higher (~10 5 cm-1), which is very important factor regarding solar conversion efficiency. Hot point probe measurements show that the films possess ntype electrical conductivity.
Journal of Materials Science: Materials in Electronics, 2020
In the current study, thin films of tin sulfide (SnS) were grown by sol-gel spincoating technique deposited on glass substrates. The obtained thin films were characterized using X-ray diffraction (XRD), photoluminescence (PL) and UV-Vis spectrometer and the four point technique, respectively. The effect of annealing temperature on the SnS properties has been studied. The XRD results reveal that the films annealed at 500°C have good crystalline quality with orthorhombic phase. Fourier-transform infrared spectroscopy (FTIR) spectra shows the Sn-S bond. The photoluminescence spectra showed two categories of band emission. The optical parameters (a, e, n, k, E g , and r op) were determined using UV-Vis spectroscopy. Moreover, the obtained results were compared to the theatricals results obtained with density functional theory (DFT) method using ab-initio approach. The optical and the electrical properties of the SnS Layers annealed at 400°C and 500°C offer the best possibility for their utilization in photovoltaic applications.