SnS Powder Research Articles

Vertically aligned 2D tin sulfide (SnS) nanoplates for selective detection of ethanol gas at room temperature

Abstract Detection of ethanol gas quickly and efficiently at room temperature is crucial for ensuring environmental, human as well as industrial safety. In this work, we have demonstrated a chemiresistive room temperature ethanol gas sensor based on vertically aligned tin sulfide (SnS) nanoplates. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) analysis have revealed the formation of orthorhombic, vertically aligned SnS nanoplates with high specific surface area. The sensor has been fabricated by depositing the SnS powder sample on ITO sheets using electrophoretic deposition (EPD), followed by the deposition of silver (Ag) electrodes using the thermal evaporation technique. The sensor obtained has exhibited a response value (R g/R a) of 17.4–400 ppm ethanol gas concentration, a quick response, and a recovery time of 12.4 s and 20.2 s at room temperature. The sensor has demonstrated long-term stability of 15 min, impressive selectivity, and remarkable repeatability across three successive test cycles of ethanol gas at 400 ppm. Based on the experimental sensing results, a plausible mechanism has been proposed for the sensor. The sensing response of SnS-based sensor at room temperature expands its potential for innovative applications across industries, marking a significant advancement in sensing technology.

Insights to the production of SnS-cubic thin films by vacuum thermal evaporation for photovoltaics

Thin films of SnS-CUB with a lattice constant of 11.6 Å, 32 units of SnS per cell and an optical bandgap (E g) of 1.7 eV (direct), are mostly produced by chemical techniques. This cubic polymorph is distinct from its orthorhombic polymorph (SnS-ORT) with an E g of 1.1 eV. This work is on the deposition of SnS-CUB thin films of 100–300 nm in thickness by thermal evaporation at substrate temperatures of 400 °C–475 °C on glass or on a chemically deposited SnS-CUB thin film (100 nm). Under a slow deposition rate (3 nm min−1) from a SnS powder source at 900 °C, the thin film formed on a SnS-CUB film or glass substrate at 450 °C is SnS-CUB. At a substrate temperatures of 200 °C–350 °C, the thin film is of SnS-ORT. A low atomic flux and a higher substrate temperature favor the growth of SnS-CUB thin film. The E g of the SnS-CUB film is nearly 1.7 eV (direct gap), and that of the SnS-CUB film is 1.2 eV (indirect gap). The electrical conductivity (σ) of SnS-CUB and SnS-ORT films are 10–7 and 0.01 Ω–1 cm−1, respectively. A proof-of-concept solar cell of the SnS-CUB thin film showed an open circuit voltage of 0.478 V, compared with 0.283 V for the SnS-ORT solar cell. The insights to the deposition of SnS-CUB and SnS0.45Se0.55-CUB (E g, 1.57 eV; σ, 0.02 Ω−1 cm−1) thin films by vacuum thermal evaporation offer new outlook for their applications.

Ultraviolet to near infrared wavelength independent SnS-graphene hybrid thin film photodetector from nanocolloids

It is crucial and imperative to produce wavelength-independent photodetectors as most of the reported devices are limited by their operating wavelength region. We report graphene incorporated tin sulfide (SnS) hybrid thin films as photodetectors operational in the ultrabroadband range of wavelength using their nanocolloids. SnS nanocolloids obtained by Pulsed Laser Irradiation in Liquid (PLIL) performed by irradiating SnS powder using 532 nm laser output (Nd:YAG) is the first report on SnS by PLIL. Into this nanocolloid, graphene was ultrasonically dispersed. SnS-graphene hybrid films were deposited by spin-coating followed by annealing in vacuum. The morphological study of the films revealed graphene layers hybridized with spherical SnS nanoparticles. Raman analysis, X-ray diffraction and X-ray photoelectron spectroscopy results confirmed the phase, structure and chemical composition. A bandgap of 2.1–2.0 eV was obtained for the annealed SnS films and graphene addition helped in extending the absorption range over the entire UV–Vis-NIR reducing the bandgap values to 1.8–1.5 eV. The films showed high photoresponse independent of the different wavelengths of illumination. The hybrid photodetector exhibits a specific detectivity of 107 Jones and a responsivity of 10-5 AW−1. The SnS-graphene hybrid photodetectors, being wavelength-independent, are a promising candidate for optoelectronic applications.

Preparation of high-quality SnS thin films for self-powered photodetectors and solar cells using a low-temperature powder technique

The binary compound tin-sulfide (SnS) is a promising absorber semiconductor for visible photodetectors and solar cells due to its optimum forbidden band gap and high absorption coefficient. It was shown in this study that high quality SnS powder can be prepared by a powder preparation method at relatively low temperatures. The resulting powder was used to deposit SnS layers via thermal evaporation. The SnS layers were then grown on molybdenum coated and uncoated glass substrates. The crystalline structures of the films prepared on molybdenum coated substrates were reported to be enhanced. According to the XRD and Raman measurements, the thin films grown on both substrates did not contain foreign phases such as SnS2 and Sn2S3. The optical investigation of samples revealed a high absorption coefficient that exceeded ∼8 × 104 cm−1 at 700 nm wavelength. Furthermore, the optical and electrical measurements show that SnS thin films exhibit p-type conductivity and can be employed in heterojunction solar cells and self-powered photodetectors with a desired forbidden band gap of ∼1.5 eV. A short circuit current density of ∼1.5 mA/cm2, an open circuit voltage of ∼113 mV, and an efficiency of 0.05% were obtained for the Ag/SnS/CdS/ITO/glass structured solar cell. The on/off current ratio of the prepared self-powered Ag/SnS/CdS/ITO/glass structured photodetector was as high as 28316.76 ± 1588 at zero bias. On the other hand, it was shown that the detectivity of the self-powered photodetector device can be tuned between (1.201 ± 0.011)x108 and (1157.83 ± 2.39)x108 Jones by adjusting the substrate temperature. A responsivity value as high as (15149.47 ± 31.31) μA/W has been achieved at zero bias.

Hydrothermal synthesis of undoped and inner transition metals (neodymium (Nd), gadolinium (Gd)) doped tin monosulfide (SnS) nanostructures: Comparative study of the morphological, opto-magnetic properties and antibacterial performance

Undoped SnS, and Nd and Gd-doped SnS nanostructures were fabricated by hydrothermal approach. The XRD study for the Gd-doped SnS powder proved the formation of an orthrhombic crystal structure. The SEM study reveals the particles’ surface altered by introducing the Nd and Gd element into the SnS materials. Undoped and doped SnS materials have ferromagnetic characters detected, along with the distinct coercive force and intense magnetization revealed by VSM study. Significantly reduced band gap values have been observed for doped SnS in the optical absorption spectra. The antibacterial activity of prepared materials was tested, and the results have been discussed in detail.

Influence of nanostructured SnS thin films for visible light photo detection

SnS thin films were deposited onto glass substrates with different substrate temperature of 50 °C, 100 °C, 150 °C and 200 °C by vacuum thermal evaporation at 10 −5 Torr using prepared SnS powder sample as evaporated targets. The structural, electrical and optical properties of substrate temperature influenced SnS films were studied using standard characterization techniques. The X-ray diffraction (XRD) showed that the deposited films are of orthorhombic crystal structure and are polycrystalline in nature. Energy dispersive spectroscopy (EDS) revealed the presence of Sn and S elements in the deposited film and its stoichiometry. Raman studies confirmed the formation of orthorhombic phase SnS films. The optical properties such as film thickness (d), absorption coefficient (α), optical band gap (E g ), refractive index (n) and extinction coefficient (k) of the deposited thin films are estimated from the optical transmittance measurements. The optical band gap values were found to be in the range of (1.843–2.075 eV). The visible photoresponsivity and specific detectivity of the films also increased with increasing the substrate temperature. • Nanostructured SnS thin films were deposited with varying substrate temperature. • Photoresponsivity and specific detectivity increases with substrate temperature. • 200 °C substrate temperature film shown relatively enhanced visible light photodetection than room temperature (RT) film.

Tin Sulfide/Gallium Oxide Heterojunctions for Solar Water Splitting

Tin (II) sulfide (SnS) is a promising semiconductor material for next‐generation solar energy conversion due to its favorable bandgap, elemental abundance, low toxicity, and low cost. A major challenge, however, lie in the low open circuit voltages that are typically obtained in SnS‐based devices. Herein, a low‐cost solution‐phase deposition technique is used to prepare SnS thin films and investigate different junction materials (Ga2O3 and In2S3) to improve the photovoltage in SnS‐based water splitting photocathodes. Molecular inks are prepared by dissolving SnS powder in solvent mixtures of ethylenediamine and 1,2‐ethanedithiol. SnS thin films are then successfully deposited by spin coating the inks onto substrates, followed by a heat treatment at 350°C in an inert atmosphere. With a photoelectrode based on a SnS/Ga2O3 heterojunction, an onset potential of +0.25 V versus reversible hydrogen electrode (RHE) is achieved for photoelectrochemical hydrogen evolution in pH 7 phosphate buffer, which is until now the earliest onset potential (highest photovoltage) among nontoxic replacements to CdS junctions in SnS‐based water splitting systems.

Self-confined vapour-liquid-solid growth of SnS/SiOx core/shell nanowires

Tin sulfide/silicon oxide (SnS/SiOx) core/shell nanowires (NWs) were synthesized by a catalyst-free chemical vapor deposition (CVD) technique using SnS powder as the source material. The morphology and microstructure of the as-prepared NWs were characterized, and it was found that the NWs have core/shell structures composed of crystalline orthorhombic SnS cores and amorphous SiOx shells. Interestingly, there were holes encapsulated in the core/shell NWs to separate the SnS cores into segments. Based on the examinations on the morphology evolution of the NWs, we propose a self-confined vapour-liquid-solid (VLS) growth mechanism, in which silicon oxide shells confined the lateral growth of SnS cores resulting in the formation of core/shell NWs.

Application of sonochemically synthesized SnS and SnS2 in the electro-Fenton process: Kinetics and enhanced decolorization

SnS and SnS2 powders were synthesized with the use of ultrasound. The indirect sonication was applied with ultrasound frequency 40kHz and acoustic power 38W/L. Products of syntheses were examined with PXRD, TEM, EDX, XPS, and UV-Vis (the Tauc method) investigations. The resulting microparticles were used for tip coating of copper cathodes. These electrodes were used in the degradation of model azo-dye Metanil Yellow by the electro-Fenton process. The efficiencies of degradation using copper, SnS-coated copper, and SnS2-coated copper cathodes are compared. Kinetics of degradation of Metanil Yellow in the electro-Fenton process with the application of three different cathodes is also investigated. It was found that the degradation follows pseudo-first-order and that SnS-coated copper cathode improves the efficiency of degradation, while SnS2-coated copper cathode decreases the efficiency of degradation.

Beyond 10% efficient Cu2ZnSn(S,Se)4 solar cells: Effects of the introduction of SnS powder during selenization process

Cu2ZnSn(S,Se)4 (CZTSSe) has received considerable attention as the promising absorber for thin-film solar cells. For traditional selenization process, the issues of Sn-loss, lower S/(S + Se) ratio, and unsuitable back contact interface extensively exist in CZTSSe solar cells. In present work, SnSe and SnS powder is introduced during selenization process, respectively. The effects of SnSe and SnS powder on CZTSSe films and the Mo/CZTSSe interface have been comprehensively studied. We discover that SnS not only can provide the Sn-contained vapor in selenization process but also offer S-vapor. Due to the presence of Sn-contained vapor, the number of voids in the CZTSSe absorber and Mo/CZTSSe interface decreases remarkably and the Sn-loss is effectively suppressed. The thickness of Mo(S,Se)2 layer is significantly reduced, and the S/(S + Se) ratio in CZTSSe bulk obviously increases owing to the presence of S-vapor. As a consequence, the open-circuit voltage and fill factor of the solar cell significantly increase and the CZTSSe solar cell with efficiency of 10.07% (total area) is successfully fabricated.

Morphology and Texture Engineering Enhancing Thermoelectric Performance of Solvothermal Synthesized Ultralarge SnS Microcrystal

With intrinsically strong anisotropy, layer-structured SnS and SnSe-based thermoelectric materials are attracting extensive attention. In this study, we synthesized ultralarge SnS microcrystal through a facile solvothermal method. It is found that the morphology of as-synthesized SnS powders can be tuned from plate into belt shapes with reduction in the amount of NaOH. After sintering, the pellets sintered from larger SnS belts showed strengthened anisotropy due to texturing effect compared with those sintered from SnS plates, and led to enhanced electrical performance along the in-plane direction ({111}-preferred). The tuned reaction condition with reduction in the amount of NaOH also increased the Sn vacancies, leading to reduced band gap, shifted Fermi level, and subsequently enhanced hole concentration. Consequently, the overall thermoelectric performance was enhanced with reducing the amount of NaOH. This study indicates texture engineering is effective in tuning anisotropy of polycrystalline SnS, enhancing the thermoelectric performance, and can be realized via morphology engineering.

Mechanism on the modified sulfurization process for growing large-grained Cu2ZnSnS4 thin films

A facile and effective sulfurization method is developed to grow the large-grained Cu2ZnSnS4 (CZTS) films. This method involves short duration of high temperature and adding SnS powder. The roles of SnS powder to promote the growth of CZTS large grains are comprehensively investigated. SnS can suppress the loss of Sn in CZTS precursor during the sulfurization process. More importantly, the reaction between SnS and S leads to the formation of SnS2 intermediate phase, which is a fluxing agent under high S atmosphere and more easily reacts with other secondary phases. Consequently, large grains of CZTS through the whole film thickness are successfully prepared with the help of SnS2. Furthermore, the CZTS solar cell with efficiency of 5.8% (active area efficiency 6.4%) without MgF2 anti-reflection coating is fabricated. The severe carrier recombination within the heterojunction interface is the major factor limiting device efficiency. The optimization for the heterojunction interface is expected to further improve efficiency.

Cu2SnS3 based thin film solar cells from chemical spray pyrolysis

A simple and eco-friendly method for solution processing of Cu2SnS3 p-type semiconductor absorbers using a water-based precursor solution is presented. Cu2SnS3 layers were processed by chemical spray pyrolysis deposition of the precursor solution onto Mo-coated glass substrates at 350 °C. The as-prepared layers were placed inside a graphite susceptor with S and SnS powders and were annealed in a tube furnace at 550 °C. The impact of the annealing step on structural, morphological and device characteristics of the prepared layers was studied.The as-prepared layers were crack-free with fine grains and dominant tetragonal Cu2SnS3 structure. A denser and compact Cu2SnS3 layer with larger grains was formed upon annealing accompanied by a structural phase transition from the tetragonal polymorph to the monoclinic phase. The as-prepared Cu2SnS3 layers showed no photovoltaic activity, whereas the annealed layers showed a device efficiency of 0.65%. A short air annealing of the complete Cu2SnS3 device at 250 °C improved the overall device performance and increased the device efficiency to 1.94%. Mechanical removal of shunt paths led to Cu2SnS3 device with 2.28% efficiency.

Annealing temperature of nanostructured SnS on the role of the absorber layer

This study reports an experimental and theoretical research on the optimal annealing temperature, absorber layer thickness, and operational temperature of nanostructured SnS-based solar cells fabricated using the ethyl cellulose binder. The SnS powder was synthesized by a co-precipitation method. Characterization of the prepared powder by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) revealed polycrystalline orthorhombic nanostructures with a mean size lower than 50 nm while UV–Vis-NIR and photoluminescence (PL) spectroscopies showed the suitability of the nanostructures for photovoltaic applications. According to the initial assessments, the SnS nanostructures were used to fabricate solar cell devices by depositing a blocking layer (BL) and an electron transport layer (ETL), as the buffer layers, and annealing the absorber SnS layer at 200–500 ℃. To determine the optimal annealing temperature, different measurements were performed. Based on the obtained results, the sample annealed at the lowest temperature (200 ℃) can present the highest efficiency (0.58%) by producing the highest carrier concentration and minimizing the scatter of carrier transportation in its crystalline lattice. Also, this sample shows best external quantum efficiency (EQE) about 44% and the lowest charge-transfer resistance by improving carrier collection. Finally, SCAPS simulation program was conducted evaluate the effect of the absorber's thickness and the operational temperature on the performance of the fabricated solar cells. The simulation results were further validated by conducting additional experiments. Obtained results show an increase in thickness and operational temperature resulted in a corresponding increase and decrease in the efficiency of our solar cells, respectively.

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.

Fabrication of Cu2SnS3 thin films by ethanol-ammonium solution process by doctor-blade technique

In the present study, a low-cost and simple method is applied to fabricate Cu2SnS3 (CTS) thin films. Namely CTS thin films are prepared by a doctor-blade method with a slurry dissolving the Cu2O and SnS powders obtained from CBD reaction solution into ethanol-ammonium solvents. Series of characterization methods including XRD, Raman spectra, SEM and UV-Vis analyses are introduced to investigate the phase structure, morphology and optical properties of CTS thin films. As a result, monoclinic CTS films have been obtained with the disappearance of binary phases CuS and SnS2 while increasing the annealing temperature and time, high quality monoclinic CTS thin films consisting of compact and large grains have been successfully prepared by this ethanol-ammonium method. Moreover, the secondary phase Cu2Sn3S7 is also observed during the annealing process. In addition, the post-annealed CTS film with a band-gap about 0.89 eV shows excellent absorbance between 400 and 1200 nm, which is proper for the bottom layer in multi-junction thin film solar cells.

Facile strategy for the formation of tin monosulfide thin films by rapid thermal annealing

A simple but facile way to form phase-pure tin monosulfide (SnS) thin films is proposed using a rapid thermal annealing (RTA) process. SnS powder and substrate were loaded into a vacuum-sealed quartz ampoule and treated by RTA at 500°C for 10min. This allowed the formation of single-phase SnS films. The densely packed morphology and phase purity of the films were confirmed by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. A preliminary thin-film solar cell was fabricated that demonstrated the efficiency of 0.42%.

Structural and dielectric study of nano-crystalline single phase Sn1−xNixS (xNi=0–10%) showing room temperature ferromagnetism

SnS is a promising IV-VI semiconductor, which is very less explored for diluted magnetic semiconducting and dielectric applications. In this study, the Ni doping (xNi=0–10mol%) effects on SnS host lattice were investigated. A simple and low cost co-precipitation technique was employed to grow Ni doped SnS powders. The X-ray diffraction confirmed single phase orthorhombic structure with a nano-crystalline nature that was further verified through the surface structure observed by scanning electron microscopy. Near edge x-ray absorption fine structure spectroscopy revealed a shift in the Ni absorption edge towards higher energy, depicting the formation of Ni+3 oxidation state. The impedance measurements, in the frequency range 1kHz to 20MHz, depict that owing to the excellent sensitivity to the electromagnetic radiations at the low energy, the Ni doped SnS finds potential applications in various energy related devices. Vibrating sample magnetometer measurements have elucidated room temperature ferromagnetism, which depicts potential memory device applications.

Composition‐ratio control of CZTS films deposited by PLD

The control of the composition of the CZTS polycrystals has been examined. CZTS poly‐crystal, ZnS, and SnS powders were mixed for adjusting the composition and were sintered at temperature of 400 °C. We evaluated polycrystal with the molar ratios of Cu/(Zn+Sn) = 0.79, Zn/Sn = 1.04, and S/(Cu+Zn+Sn) = 0.95. Then, we prepared CZTS film by PLD method using the CZTS polycrystal as a target. Composition content of the film was also evaluated to be the molar ratios of Cu/(Zn+Sn) = 1.14, Zn/Sn = 1.04, and S/(Cu+Zn+Sn) = 0.69. The film indicats slightly Cu‐rich, and S‐poor compositions, and no change of Zn/Sn rate. Definitely, we successfully performed composition control and improvement of composition uniformity for polycrystals by using the source materials of CZTS, ZnS, and SnS. Additionally, we prepared homogeneous CZTS film with either a kesterite or a stannite structure by PLD method.

Efficiency enhancement by adding SnS powder during selenization for Cu2ZnSn(S,Se)4 thin film solar cells

A two-step process with post-annealing of stacked precursors has been widely used for Cu2ZnSn(S,Se)4 (CZTSSe) absorbers. However, no simple approach is currently available for simultaneously tuning the S/(S+Se) ratio and avoiding tin loss issue in CZTSSe films, which are critical factors to achieve high efficiency. In this work, we demonstrate by simply adding SnS powder during selenization, we can eliminate the tin loss and also control the S/(S+Se) ratio. Furthermore, we can suppress the formation of Mo(S,Se)2 during selenization. Based on thermodynamic calculations, we propose SnS powder reacts with selenium to form SnSe and releases sulfur vapor during selenization. The Sn-contained vapor avoids tin evaporation from CZTSSe. By varying the amount of SnS powder, the partial pressure ratio of sulfur to selenium can be tuned; therefore, the film composition and band bap of CZTSSe can be changed. The presence of sulfur partial pressure also dramatically decreases the formation of Mo(S,Se)2 during selenization. The efficiency is substantially boosted from 3.97% to 7.35% by adding SnS powder during selenization. Our approach realizes one-step sulfo-selenization, providing a general tuning knob for compositional control of CZTSSe absorbers, which shines light on various process developments of CZTSSe absorbers by post-annealing vacuum- or solution-fabricated precursors.