Tin Monosulfide Research Articles

Atomic layer deposition of tin monosulfide thin film using Sn(acac)2 and H2S

In this study, we deposited tin monosulfide (SnS) thin film using Tin(II) 2,4-pentanedionate [Sn(acac)2] precursor and hydrogen sulfide (H2S) reactant. And we performed post annealing to improve the crystallinity of SnS thin films. The process window was 130 °C–150 °C, and the growth rate was 0.34 Å/cycle. To investigate crystallinity and the phase of SnS thin films, grazing incidence x-ray diffraction (GI-XRD) and Raman spectroscopy were performed. SnS thin films showed a single orthorhombic phase after annealing. In addition, transmission electron microscopy (TEM) was utilized to confirm the two-dimensional (2D) layered structure of SnS thin films. Post-annealed SnS thin film clearly showed a 2D layered structure. X-ray photoelectron spectroscopy (XPS) was performed to confirm the bonding state of the thin film. The results indicated that the SnS thin film only shows binding energies corresponding to the oxidation states of Sn2+ in the Sn 3d spectra and S2- in the S 2p spectra. Ultraviolet–visible (UV–vis) spectroscopy and ultraviolet photoelectron spectroscopy (UPS) were performed to confirm the optical properties and to calculate the band structure of the thin film. All of SnS thin film showed a p-type characteristic. The post-annealed SnS thin films exhibited better electric properties, confirmed by Hall measurement.

Electronic and thermal transport engineering of a highly earth-abundant and low-cost Sn-based thermoelectric material

Tin monosulfide (SnS), composed of abundant, low-cost, and environmentally friendly elements, has garnered significant attention in the field of thermoelectrics due to its analogous electron and phonon transport properties to SnSe. However, undoped SnS exhibits a limited charge carrier concentration, resulting in poor electrical conductivity. In this study, a dual doping approach was employed, introducing both cationic (Na and Pb) and anionic (Se and Te) dopants into polycrystalline SnS. This approach yielded a notable enhancement in electrical properties and a reduction in thermal conductivity. As a result of these modifications, the figure of merit (zT) reached 0.38 at approximately 525 K. Specifically, the power factor increased to 2.25 μWcm−1K−2, while the total thermal conductivity was reduced to 0.3 Wm−1K−1. These findings highlight the potential of synergistic cation and anion doping strategies to significantly improve the thermoelectric performance of SnS at relatively lower temperatures, offering a pathway for further exploration of cost-effective thermoelectric materials based on SnS.

Tailoring the opto-electronic properties of SnS thin films by indium doping and fabrication of heterojunction diodes

This study comprehensively investigates the effect of Indium (In) doping on the structural, morphological, and optoelectronic properties of tin mono-sulfide (SnS) thin films deposited using co-evaporation. X-ray diffraction studies identified the orthorhombic phase of SnS. Raman analysis confirmed the formation of SnS by co-evaporation. Morphological analysis revealed uniform coating of the films, a transition from rod-like to regular grain-like structures with increased In doping. A systematic reduction in Sn concentration, with the increase in In is observed in EDS, indicating the substitutional doping of In. The decrease in root mean square roughness with In incorporation suggests smoother film surfaces. The films demonstrated a pronounced improvement in optoelectronic properties, with a notable increase in the absorption coefficient and a bandgap reduction from 2.18 eV to 1.74 eV, resulting from In doping. A significant enhancement in electrical characteristics is observed, including a 140 % increase in conductivity and a systematic rise in carrier concentration with higher In doping levels. Heterojunction devices are fabricated with structure <FTO/Al:ZnO/In:SnS/Ag> having a series resistance of 29.9 Ω having an ideality factor of 2.8.

Role of triethanolamine complexing agent in chemical bath deposition of tin sulfide thin films: Microstructural and optical properties

This paper reports the experimental results studying the structure, optical and dielectric properties of tin monosulfide thin films. Tin monosulfide (SnS) films were deposited on glass substrate by chemical bath deposition to study the role of triethanolamine (TEA: complexing agent) concentration on the film properties. X-ray diffraction spectra reveal that the films exhibit mainly cubic phase which remain stable over the range of TEA concentration (3.0 M − 5.0 M). FTIR spectra indicate the S-Sn bond stretching in all films. Raman spectroscopy analysis shows the presence of minor trace of secondary SnS2 phase (along with main cubic π-SnS phase) in all films. SEM micrographs show cauliflower-like surface morphology of all films. Optical results reveal that the films possess high value of absorption coefficient (≥105 cm−1) in the visible region. Direct optical transition behavior is observed in all films. From Tauc plots, the calculated optical band gap (Eg) varies from 1.79 eV to 1.91 eV with the variation in TEA concentration. The dielectric constant, refractive index and an extinction coefficient are also calculated and observed to decrease with increasing TEA concentration. Experimental results suggest that an appropriate concentration of a complexing agent (TEA) can be chosen to obtain crystalline films without deterioration of crystalline structure and phase, not effecting Eg significantly.

Impact of a precise pH value change on the characteristics of deposited tin monosulphide films onto a flexible substrate

The chemical bath deposition technique (CBD) is considered the cheapest and easiest compared with other deposition techniques. However, it is highly sensitive to effective parameter deposition values such as pH, temperature, and so on. The pH value of the reaction solution has a direct impact on both the nucleation and growth rate of the film. Consequently, this study presents a novel investigation into the effect of a precise change in the pH reaction solution value on the structural, morphological, and photoresponse characteristics of tin monosulphide (SnS) films. The films were grown on a flexible polyester substrate with pH values of 7.1, 7.4, and 7.7. The X-ray diffraction patterns of the grown films at pH 7.1 and 7.4 confirmed their polycrystalline nature. Additionally, an observed alteration in the crystal structure occurred as the pH value increased from 7.1 to 7.4, resulting in a transition from an orthorhombic crystal structure to a cubic crystal structure. In contrast, the XRD pattern of the grown film at pH 7.7 revealed that it was amorphous. The field-emission scanning electron microscopy images revealed a flower-like morphology for the grown film at 7.1, whereas the grown films at 7.4 and 7.7 revealed a grain morphology. The results also showed that the pH values were also having an important effect on the energy gap value (Eg) of films; the Eg values were 1.46, 1.57, and 1.65 eV for pH 7.1, 7.4, and 7.7, respectively. The photodetectors fabricated using grown films exhibited excellent photoresponse characteristics when subjected to near-infrared (750 nm) illumination. It was also demonstrated that the photodetector using the cubic structure film possessed faster response times and greater sensitivity than the photodetector using the orthorhombic structure film.

The effect investigates of temperature on the optical and electrical properties of sprayed SnS: experimental and theoretical study

In this study, Tin monosulfide SnS semiconductor absorbers was deposited by chemical spray pyrolysis route on the glass substrate. We examined the impact of substrate temperature on the structural, morphological, linear optical and electrical characteristics of SnS absorber at many substrate temperatures such as 50 °C, 375 °C and 400 °C. The SnS films have been analysed by diverse techniques like X-ray diffraction, Raman spectroscopy, Scanning electron microscopy and UV-Vis spectrophotometer. The X-ray diffraction (XRD) spectra revealed that the SnS crystallize in the orthorhombic crystal system with the apparition of the preferential crystallographic direction oriented along (111) planes. The SEM micrographs indicate a great uniformity and granular morphological surface of SnS films. Linear optical constants such as energy gap (Eg), coefficient of extinction (k), index of refraction (n), optical conductivity (σopt), as well as the electrical properties confirm the suitable application of SnS thin films as absorber layer in the optoelectronic device applications. Additionally, we have applied the density functional theory DFT and GGA generalized gradient approximation to study the electronic characteristics; as a result of the electronic band structure the SnS absorber has a suitable energy gap.

Heteroepitaxial Growth of Black Phosphorus on Tin Monosulfide.

Black phosphorus (Black P), a layered semiconductor with a layer-dependent bandgap and high carrier mobility, is a promising candidate for next-generation electronics and optoelectronics. However, the synthesis of large-area, layer-precise, single crystalline Black P films remains a challenge due to their high nucleation energy. Here, we report the molecular beam heteroepitaxy of single crystalline Black P films on a tin monosulfide (SnS) buffer layer grown on Au(100). The layer-by-layer growth mode enables the preparation of monolayer to trilayer films, with band gaps that reflect layer-dependent quantum confinement.

Van der Waals Epitaxy, Superlubricity, and Polarization of the 2D Ferroelectric SnS.

Tin monosulfide (SnS) is a two-dimensional layered semiconductor that exhibits in-plane ferroelectric order at very small thicknesses and is of interest in highly scaled devices. Here we report the epitaxial growth of SnS on hexagonal boron nitride (hBN) using a pulsed metal-organic chemical vapor deposition process. Lattice matching is observed between the SnS(100) and hBN{11̅0} planes, with no evidence of strain. Atomic force microscopy reveals superlubricity along the commensurate direction of the SnS/hBN interface, and first-principles calculations suggest that friction is controlled by the edges of the SnS islands, rather than interface interactions. Differential phase contrast imaging detects remnant polarization in SnS islands with domains that are not dictated by step-edges in the SnS. The growth of ferroelectric SnS on high quality hBN substrates is a promising step toward electrically switchable ferroelectric semiconducting devices.

Deposition of SnS thin films on various substrates at room temperature

This study describes a modified SILAR technique for depositing Tin monosulphide (SnS) thin films on diverse substrates, such as glass, ITO coated glass, and OHP sheet, all at room temperature. This simple, less expensive, environmentally friendly, and industrially scalable method allows excellent control over the deposition rate and thickness, as well as many experimental flexibilities. The advantages of depositing films at room temperature include energy efficiency, cost-effectiveness, and suitability for heat-sensitive materials. The deposited SnS thin films underwent comprehensive analysis through XRD, FESEM, EDAX, XPS, TGA, and UV–visible spectroscopy to thoroughly understand their properties. The results showed that the films were polycrystalline, orthorhombic, single-phase, and nearly stoichiometric, with a bandgap value in the visible region. The deposition conditions were optimized to achieve high-quality thin films, and the impact of substrate variations on film characteristics was also investigated. The study showcased the simplicity of doping in the modified SILAR process. Furthermore, the study demonstrated the photocatalytic degradation effectiveness of SnS thin films against the dye Rhodamine B. Various analyses, including UV-visible spectroscopy studies, ROS scavenger tests, ROS indicator tests, and kinetic analysis, were performed. The photodegradation process was effectively described by the Langmuir-Hinshelwood (L-H) mechanism.

Impact of iron doping on the structural and optical properties of nano Tin mono-sulfide SnS

Impact of iron doping on the structural and optical properties of nano Tin mono-sulfide SnS

Nanosensitizer-mediated augmentation of sonodynamic therapy efficacy and antitumor immunity

The dense stroma of desmoplastic tumor limits nanotherapeutic penetration and hampers the antitumor immune response. Here, we report a denaturation-and-penetration strategy and the use of tin monosulfide nanoparticles (SnSNPs) as nano-sonosensitizers that can overcome the stromal barrier for the management of desmoplastic triple-negative breast cancer (TNBC). SnSNPs possess a narrow bandgap (1.18 eV), allowing for efficient electron (e−)-hole (h+) pair separation to generate reactive oxygen species under US activation. More importantly, SnSNPs display mild photothermal properties that can in situ denature tumor collagen and facilitate deep penetration into the tumor mass upon near-infrared irradiation. This approach significantly enhances sonodynamic therapy (SDT) by SnSNPs and boosts antitumor immunity. In mouse models of malignant TNBC and hepatocellular carcinoma (HCC), the combination of robust SDT and enhanced cytotoxic T lymphocyte infiltration achieves remarkable anti-tumor efficacy. This study presents an innovative approach to enhance SDT and antitumor immunity using the denaturation-and-penetration strategy, offering a potential combined sono-immunotherapy approach for the cancer nanomedicine field.

Stability and Efficiency Enhancement of Antimony Selenosulfide Solar Cells with Inorganic SnS‐Modified Nickel Oxide Hole Transport Materials

Antimony selenosulfide (Sb2(S,Se)3) has been emerging as a promising light absorber owing to its tunable bandgap (1.1–1.7 eV), high absorption coefficient (&gt;105 cm−1), and excellent phase and environmental stability. Lithium salt‐doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxy‐phenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD) has been generally used as the hole transport layer (HTL) in these high‐efficiency antimony selenosulfide solar cells so far. However, the lithium‐ion reactions and migration in this HTL may cause serious challenges for the stability of these solar cells. Herein, stable and low‐cost tin monosulfide (SnS) nanoparticles surface‐modified nickel oxide (NiOx) as an inorganic hole transport layer to fabricate highly efficient and stable all‐inorganic solar cells is developed. It is found that NiOx films not only demonstrate a higher conductivity but also form better energy band alignment after SnS surface treatment. Consequently, the power conversion efficiency of the full inorganic Sb2(S,Se)3 solar cells increases from 4.85% to 6.41%. Most importantly, the devices also demonstrate much improved thermal, moisture, and long‐term stabilities as compared to the solar cells with spiro‐OMeTAD hole transport layer.

Low-Temperature Centimeter-Scale Growth of Layered 2D SnS for Piezoelectric Kirigami Devices.

Tin monosulfide (SnS) is a promising piezoelectric material with an intrinsically layered structure, making it attractive for self-powered wearable and stretchable devices. However, for practical application purposes, it is essential to improve the output and manufacturing compatibility of SnS-based piezoelectric devices by exploring their large-area synthesis principle. In this study, we report the chemical vapor deposition (CVD) growth of centimeter-scale two-dimensional (2D) SnS layers at temperatures as low as 200 °C, allowing compatibility with processing a range of polymeric substrates. The intrinsic piezoelectricity of 2D SnS layers directly grown on polyamides (PIs) was confirmed by piezoelectric force microscopy (PFM) phase maps and force-current corroborative measurements. Furthermore, the structural robustness of the centimeter-scale 2D SnS layers/PIs allowed for engraving complicated kirigami patterns on them. The kirigami-patterned 2D SnS layer devices exhibited intriguing strain-tolerant piezoelectricity, which was employed in detecting human body motions and generating photocurrents irrespective of strain rate variations. These results establish the great promise of 2D SnS layers for practically relevant large-scale device technologies with coupled electrical and mechanical properties.

Defect-mediated saturable absorption and carrier dynamics in tin (II) monosulfide quantum dots.

Tin (II) monosulfide (SnS) has attracted considerable attention in emerging photonics and optoelectronics because of high carrier mobility, large absorption coefficient, anisotropic linear and nonlinear optical properties, and long-time stability. In this Letter, we report third-order nonlinear absorption and refraction of SnS quantum dots (QDs). Under excitation with 800-nm femtosecond pulses, QDs exhibit saturable absorption (saturation intensity ∼ 47.69 GW/cm2) and positive refractive nonlinearity (nonlinear refraction coefficient ∼ 1.24 × 10-15 cm2/W). Nonetheless, we investigate charge carrier dynamics using femtosecond transient absorption spectroscopy and propose the presence of midgap defect states which not only dictate carrier dynamics but also give rise to nonlinear optical properties in SnS QDs.

High-Pressure Synthesis of Single-Crystalline SnS Nanoribbons.

Two-dimensional tin monosulfide (SnS) is attractive for the development of electronic and optoelectronic devices with anisotropic characteristics. However, its shape-controlled synthesis with an atomic thickness and high quality remains challenging. Here, we show that highly crystalline SnS nanoribbons can be produced via high-pressure (0.5 GPa) and thermal treatment (400 °C). These SnS nanoribbons have a length of several tens of micrometers and a thickness down to 5.8 nm, giving an average aspect ratio of ∼30.6. The crystal orientation along the zigzag direction and the in-plane structural anisotropy of the SnS nanoribbons are identified by transmission electron microscopy and polarized Raman spectroscopy, respectively. An ionic liquid-gated field-effect transistor fabricated using the SnS nanoribbon exhibits an on/off current ratio of >103 and a field-effect mobility of ∼0.7 cm2 V-1 s-1. This work provides a unique way to achieve one-dimensional growth of SnS.

Vibration‐driven Reduction of CO2 to Acetate with 100 % Selectivity by SnS Nanobelt Piezocatalysts

AbstractConverting CO2 into high‐value C2 chemicals such as acetate with high selectivity and efficiency is a critical issue in renewable energy storage. Herein, for the first time we present a vibration‐driven piezocatalysis with tin(II) monosulfide (SnS) nanobelts for conversion of CO2 to acetate with 100 % selectivity, and the highest production rate (2.21 mM h−1) compared with reported catalysts. Mechanism analysis reveal that the polarized charges triggered by periodic mechanical vibration promote the adsorption and activation of CO2. The electron transfer can be facilitated due to built‐in electric field, decreased band gap and work function of SnS under stress. Remarkably, reduced distance between active sites leads to charge enrichment on Sn sites, promoting the C−C coupling, reducing the energy barriers of the rate determining step. It puts forward a bran‐new strategy for converting CO2 into high‐value C2 products with efficient, low‐cost and environment‐friendly piezocatalysis utilizing mechanical energy.

Vibration-driven Reduction of CO2 to Acetate with 100 % Selectivity by SnS Nanobelt Piezocatalysts.

Converting CO2 into high-value C2 chemicals such as acetate with high selectivity and efficiency is a critical issue in renewable energy storage. Herein, for the first time we present a vibration-driven piezocatalysis with tin(II) monosulfide (SnS) nanobelts for conversion of CO2 to acetate with 100 % selectivity, and the highest production rate (2.21 mM h-1 ) compared with reported catalysts. Mechanism analysis reveal that the polarized charges triggered by periodic mechanical vibration promote the adsorption and activation of CO2 . The electron transfer can be facilitated due to built-in electric field, decreased band gap and work function of SnS under stress. Remarkably, reduced distance between active sites leads to charge enrichment on Sn sites, promoting the C-C coupling, reducing the energy barriers of the rate determining step. It puts forward a bran-new strategy for converting CO2 into high-value C2 products with efficient, low-cost and environment-friendly piezocatalysis utilizing mechanical energy.

Point-cavity-like carbon layer coated SnS nanotubes with improved energy storage capacity for lithium/sodium ion batteries

Tin monosulfide (SnS) is known as a prospective anode material for lithium/sodium ion batteries due to its high capacity, low cost, and easy preparation. Carbon coating is a powerful strategy to improve poor electronic conductivity and alleviate the large volume expansion of the SnS, thus achieving high electrochemical performances. However, the commonly used carbon coatings strategies usually generate interstices between the SnS and carbonaceous material, interrupting electron and ion transfer and unsatisfied accommodation of volume expansion. Herein, point-cavity-like carbon coated SnS nanotubes (CN/SnS) were synthesized by a close-knit mechanism using polyvinylpyrrolidone (PVP) and carbon nitride (g-C3N4) as carbon sources. The carbonyl group in PVP can form hexahydroxylated stannyl compound with Sn2+, and the amine group can generate CN bond with the g-C3N4 template in an aqueous solution, respectively. The unique construction of CN/SnS can successfully reinforce the electron and ion transfer capability and accommodate volume expansion. The reformative effectivity dramatically improves the energy storage properties of SnS electrode for LIBs/SIBs. The CN/SnS electrode can deliver high specific capacities of 547.7 mAh g−1 at 1.0 A g−1 after 300 cycles for lithium-ion batteries and 298.2 mAh g−1 at 0.1 A g−1 after 200 cycles for sodium-ion batteries, respectively. The structure design is practical and feasible, which could be used to develop high-performance transition metal sulfide/carbon composite anodes for LIBs and SIBs.

SnS-RGO Hybrid Nanosheets as High Performance Flexible Photodetectors and Visible-Light Photocatalysts

A straightforward solvothermal technique was used to create tin monosulfide (SnS) nanosheets that were reduced graphene oxide (RGO) bonded. On the folded RGO surface, it was discovered that the 2D SnS nanosheets had several layers that were evenly distributed. When exposed to visible light, a flexible photodetector made of PET substrate exhibits a 1.4 mA W−1 optical response, 3.5 × 107 Jones detection rate, and quick rise and fall times. (τ rise = τ decay = 0.08 s). When exposed to visible light, the methylene blue’s (MB) photocatalytic breakdown was used to test the photocatalytic performance of the synthesized SnS-RGO hybrid nanosheets. The fact that almost all of the MB dissolved in under one hour suggested that SnS-RGO nanosheets make promising high-performance photocatalysts.

SnS/MoS2 van der Waals heterojunction for in‐plane ferroelectric field‐effect transistors with multibit memory and logic characteristics

AbstractFerroelectric two dimensional (2D) materials hold great potential to develop modern miniaturized electronic and memory devices. 2D ferroelectrics exhibiting spontaneous polarization in the out‐of‐plane direction have been extensively investigated to date, but the loss of their polarization during device operation has been problematic. Although 2D materials with in‐plane ferroelectric behavior are more stable against depolarization and thus promising for memory and logic applications, experimental realization of in‐plane 2D ferroelectric devices is still scarce. Here, we demonstrate in‐plane ferroelectric field effect transistors (FETs) based on a van der Waals heterojunction (vdWHJ), which can perform multibit memory and logic operations. Tin monosulfide (SnS), a 2D material with in‐plane ferroelectricity, is partially stacked on top of a semiconducting molybdenum disulfide (MoS2) on a silicon dioxide (SiO2)‐coated silicon substrate to fabricate vdWHJ FETs in back‐gate configuration. Switching of the in‐plane polarization direction in the SnS channel modulates the contact barriers at the electrode/SnS and SnS/MoS2 interfaces, thereby creating high resistance states and low resistance states (LRS). The device exhibits a logic transfer characteristic with a high drain current on/off ratio (&gt;106) in LRS and non‐volatile memory performance with excellent retention characteristics (extrapolated retention time &gt; 10 years). With exquisite tuning of the channel resistance by SnS polarization and gate bias, we realize multiple states with distinct current levels for multibit memory and logic operations suitable for programmable logic‐in‐memory applications.image