Amorphous Sb2S3 Research Articles

Amorphous and crystalline Sb2S3 nanoparticles embedded in N/S co-doped carbon as anodes for potassium-ion batteries

Antimony trisulfide (Sb2S3) has emerged as a promising anode candidate for potassium-ion batteries (PIBs) owing to its low cost and high theoretical specific capacity. However, its large volume expansion upon K+ storage and sluggish kinetics result in poor cycling performance and rate capability. To address these challenges, rational structural design is highly desirable. Herein, we report the synthesis of amorphous and crystalline Sb2S3 nanoparticles embedded in N/S co-doped carbon composites (a-Sb2S3@NSC and c-Sb2S3@NSC) via a facile organic coating combined with subsequent carbonization and sulfidation processes. When used as a PIBs anode material, a-Sb2S3@NSC exhibits a high discharge specific capacity of 415.6 mAh g−1 after 50 cycles at 200 mA g−1 and a stable rate capability (224.8 mAh g−1 at 2 A g−1), which remarkably outperforms that of the c-Sb2S3@NSC with inferior specific capacity (311.5 mAh g−1) and poor rate capability (67.7 mAh g−1). The amorphous structure of Sb2S3 nanoparticles in a-Sb2S3@NSC provides abundant defects and structural disorder, which reduces the entropy energy and activation barrier associated with K+ incorporation, effectively facilitating the transport and storage of K+. Moreover, the synergistic interactions between amorphous Sb2S3 nanoparticles and N/S co-doped carbon can effectively improve the electron/ion reaction kinetics and buffer volume variations, thus leading to superior potassium storage performances.

Encapsulation of crystalline and amorphous Sb2S3 within carbon and boron nitride nanotubes.

The recent rediscovery of 1D and quasi-1D (q-1D) van der Waals (vdW) crystals has laid foundation for the realization of emergent electronic, optical, and quantum-confined physical phenomena in both bulk and at the nanoscale. Of these, the highly anisotropic q-1D vdW crystal structure and the visible-light optical/optoelectronic properties of antimony trisulfide (Sb2S3) have led to its widespread consideration as a promising building block for photovoltaic and non-volatile phase change devices. However, while these applications will greatly benefit from well-defined and sub-nanometer-thick q-1D structures, little has been known about feasible synthetic routes that can access single covalent chains of Sb2S3. In this work, we explore how encapsulation in single or multi-walled carbon nanotubes (SWCNTs or MWCNTs) and visible-range transparent boron nitride nanotubes (BNNTs) influences the growth and phase of Sb2S3 nanostructures. We demonstrate that nanotubes with smaller diameters had a more pronounced effect in the crystallographic growth direction and orientation of Sb2S3 nanostructures, promoting the crystallization of the guest structures along the long-axis [010]-direction. As such, we were able to reliably access well-ordered few to single covalent chains of Sb2S3 when synthesized within defect-free SWCNTs with sub-2 nm inner diameters. Intriguingly, we found that the degree of crystalline order of Sb2S3 nanostructures was strongly influenced by the presence of defects and discontinuities along the Sb2S3-nanotube interface. We show that amorphous nanowire domains of Sb2S3 form around defect sites in larger, multi-walled nanotubes that manifest inner wall defects and discontinuities, suggesting a means to manipulate the crystallization dynamics of confined sub-10 nm-thick Sb2S3 nanostructures within nanotubes. Lastly, we show that ultranarrow amorphous Sb2S3 can impart functionality onto isolable BNNTs with photocurrent generation in the pA range which, alongside the dispersibility of the Sb2S3@BNNTs, could be leveraged to easily fabricate photoresistors only a few nm in width. Altogether, our results serve to solidify the understanding of how q-1D vdW pnictogen chalcogenides crystallize within confined synthetic platforms and are a step towards realizing functional materials from ensembles of encapsulated heterostructures.

Colloidal spherical stibnite particles via high-temperature metallo-organic synthesis.

Antimony trisulfide (Sb2S3) is an emerging semiconductor with a high absorption coefficient and a bandgap in the visible range. This makes it a promising material for various electronic and optoelectronic applications. However, one of the main challenges is still the synthesis of the material, as it is usually obtained either as a nanomaterial in its amorphous form with inferior optical properties or in crystalline rod-like structures in the micrometer or sub-micrometer range, which leads to application-related difficulties such as clogging in inkjet printing or spraying processes or highly porous layers in film applications. In this study, a one-pot synthesis of highly crystalline, spherical Sb2S3 sub-micron particles is presented. The particles are growing encapsulated in a removable, wax-like matrix that is formed together with an intermediate from the precursors SbCl3 and l-cysteine. Both substances are insoluble in the reaction mixture but well-dispersable in the solvent 1-octadecene (ODE). The intermediate forms a complex crosslinked architecture whose basic building block consists of an Sb atom attached to three cysteine molecules via Sb-S bonds. Embedded in the matrix consisting of excess cysteine, ODE, and chlorine, the intermediate decomposes into amorphous Sb2S3 particles that crystallize as the reaction proceeds at 240 °C. The final particles are highly crystalline, spherical, and in the sub-micron range (420 ± 100 nm), making them ideal for further processing. The encapsulation method could not only provide a way to extend the size range of colloidal particles, but in the case of Sb2S3, this method circumvents the risk of carbonization of ligands or insufficient crystallization during the annealing of amorphous material.

Hydrophilic-amorphous versus hydrophobic-crystalline Sb2S3: The battle for higher photocatalytic efficiency

The dependence of crystallinity and hydrophilicity of the material on its photocatalytic activity is rarely explored and understood. In this work, the influence of crystallinity and surface wettability is demonstrated through the photocatalytic activity of Sb2S3 thin films. Amorphous and crystalline thin films of Sb2S3 having bandgaps of 2.36 and 1.89 eV respectively are prepared using thermal evaporation. Photocatalytic activity of both the films are evaluated in the degradation of methylene blue dye under visible light. Amorphous sample degraded 88 % of dye in 180 min of irradiation, with a reaction rate constant of 0.01/min. The crystalline sample removed only 64 % of the dye under the same condition. The analysis of the surface nature of the film using contact angle measurement revealed that, amorphous sample is hydrophilic and crystalline sample hydrophobic with water contact angles of 68° and 92° respectively. The role of surface wettability on photocatalysis is also analysed by modifying the film surface with the help of plasma treatment. The treatment reduced the hydrophilicity of the amorphous surface and at the same time transformed the crystalline surface from hydrophobic to hydrophilic. The change in the surface morphology such as formation of micro/nanostructures and variation in roughness, which contribute to the hydrophobicity is observed through AFM. The surface changes are reflected in the dye degradation efficiencies as well. The dye degradation efficiency reduced to 79 % in the amorphous sample and increased to 72 % in the crystalline sample. The study unveils the exciting efficiency of the hydrophilic, amorphous Sb2S3 films without any thermal or surface treatments as photocatalyst.

Bulk Defect Passivation for Full‐Inorganic Sb2S3 Solar Cells by Sulfur‐Atmosphere Recrystallization Process

Antimony sulfide (Sb2S3) solar cells have attracted extensive attention in silicon‐based tandem solar cells. The performance of Sb2S3 devices fabricated by the vacuum method is limited by sulfur vacancies (VS) and surface oxide defects during high‐temperature processes. Herein, amorphous Sb2S3 film based on low‐temperature rapid thermal evaporation (RTE) technique is fabricated to overcome S loss. Moreover, a sulfur‐atmosphere recrystallization strategy is further developed to obtain high‐quality absorbers from the amorphous film. The element content of Sb2S3 film is completely in accord with the stoichiometric ratio (2:3), and the surface oxides are effectively suppressed, enhancing VOC and fill factor. Compared to the control directly crystallized film, the defect concentrations of the S‐recrystallized Sb2S3 film are reduced by 61%, exhibiting better uniformity and higher PN junction quality. Ultimately, the full‐inorganic Sb2S3 solar cells (FTO/TiO2/Sb2S3/Au) achieve an efficiency of 6.25%. The S‐atmosphere recrystallization process can effectively passivate bulk defects (VS and Sb2O3) and suppress recombination to improve device performance, which will provide new prospects for vacuum method‐based Sb2S3 thin film solar cells.

Synthesis of Sb2S3 nanosphere layer by chemical bath deposition for the photocatalytic degradation of methylene blue dye.

An antimony tri-sulfide Sb2S3 nanosphere photocatalyst was effectively deposited utilizing sodium thiosulfate and antimony chloride as the starting precursors in a chemical bath deposition process. This approach is appropriate for the large-area depositions of Sb2S3 at low deposition temperatures without the sulfurization process since it is based on the hydrolytic decomposition of starting compounds in aqueous solution. X-ray diffraction patterns and Raman spectroscopy analysis revealed the formation of amorphous Sb2S3 layers. The scanning electron microscopy images revealed that the deposited Sb2S3 has integrated small nanospheres into sub-microspheres with a significant surface area, resulting in increased photocatalytic activity. The optical direct bandgap of the Sb2S3 layer was estimated to be about 2.53 eV, making amorphous Sb2S3 appropriate for the photodegradation of organic pollutants in the presence of solar light. The possibility of using the prepared Sb2S3 layer in the photodegradation of methylene blue aqueous solutions was investigated. The degradation of methylene blue dye was performed to evaluate the photocatalytic property of Sb2S3 under visible light. The amorphous Sb2S3 exhibited photocatalytic activity for the decolorization of methylene blue solution under visible light. The mechanism for the photocatalytic degradation of methylene blue has been proposed. Our results suggest that the amorphous Sb2S3 nanospheres are valuable material for addressing environmental remediation issues.

Anodic Sb2S3 electrodeposition from a single source precursor for resistive random-access memory devices

In this paper we report the use of Na3[SbS4].9H2O as a single source precursor for the electrodeposition of Sb2S3 from aqueous electrolyte at pH 9.1. We present the electrochemistry of the [SbS4]3− anion and the redox processes observed for the deposited Sb2S3 film. We show that an amorphous Sb2S3 film can be deposited by anodic electrodeposition onto glassy carbon and that the by-product that accompanies this deposition can be avoided by using a suitable pulse plating approach. Raman spectroscopy and grazing incidence X-ray diffraction were used to characterise the deposits and to show that good quality crystalline films of Sb2S3 are produced on annealing.The crystalline Sb2S3 films were screened for application in Resistive Random-Access Memory, and it was demonstrated that crystalline Sb2S3 films display typical bipolar resistive switching behaviour, and that the resistance ratio between the high resistance state and the low resistance state is approximately one order of magnitude at 1.5 V, which is sufficient for memory applications. A mechanism for the resistive switching is also proposed.

Visible and near-infrared dual band switchable metasurface edge imaging

Optical edge detection at the visible and near infrared (VNIR) wavelengths is deployed widely in many areas. Here we demonstrate numerically transmissive VNIR dual band edge imaging with a switchable metasurface. Tunability is enabled by using a low-loss and reversible phase-change material Sb2S3. The metasurface acts simultaneously as a high-pass spatial filter and a tunable spectral filter, giving the system the freedom to switch between two functions. In Function 1 with amorphous Sb2S3, this metasurface operates in the edge detection mode near 575 nm and blocks near infrared (NIR) transmission. In Function 2 with crystalline Sb2S3, the device images edges near 825 nm and blocks visible light images. The switchable Sb2S3 metasurfaces allow low cross talk edge imaging of a target without complicated optomechanics.

Compact nonvolatile 2×2 photonic switch based on two-mode interference.

On-chip nonvolatile photonic switches enabled by phase change materials (PCMs) are promising building blocks for power-efficient programmable photonic integrated circuits. However, large absorption loss in conventional PCMs (such as Ge2Sb2Te5) interacting with weak evanescent waves in silicon waveguides usually leads to high insertion loss and a large device footprint. In this paper, we propose a 2×2 photonic switch based on two-mode interference in a multimode slot waveguide (MSW) with ultralow loss Sb2S3 integrated inside the slot region. The MSW supports two lowest order TE modes, i.e., symmetric TE00 and antisymmetric TE01 modes, and the phase of Sb2S3 could actively tune two-mode interference behavior. Owing to the enhanced electric field in the slot, the interaction strength between modal field and Sb2S3 could be boosted, and a photonic switch containing a ∼9.4 µm-long Sb2S3-MSW hybrid section could effectively alter the light transmission between bar and cross ports upon the phase change of Sb2S3 with a cross talk (CT) less than -13.6 dB and an insertion loss (IL) less than 0.26 dB in the telecommunication C-band. Especially at 1550 nm, the CT in the amorphous (crystalline) Sb2S3 is -36.1 dB (-31.1 dB) with a corresponding IL of 0.073 dB (0.055 dB). The proposed 2×2 photonic switch is compact in size and compatible with on-chip microheaters, which may find promising applications in reconfigurable photonic devices.

Polarimetry analysis and optical contrast of Sb2S3 phase change material

Phase-change materials (PCMs) are the cornerstone for the development of reconfigurable and programmable photonic devices. Sb2S3 has been recently proposed as an interesting PCM due to its low-losses in the visible and near-IR. Here, we report the use of imaging polarimetry and spectroscopic ellipsometry to reveal and directly measure the optical properties of Sb2S3 both in crystalline and amorphous states obtained upon crystallization by annealing in the air of chemical bath deposited amorphous Sb2S3. The Mueller Matrix polarimetric analysis reveals the strong anisotropy of the Sb2S3 crystallites which crystallize in radial spherulitic domains in contrast to the optical isotropy of the amorphous films. A refractive index contrast of Δn = 0.5 is demonstrated while maintaining low-losses at telecommunications C-band, i.e., λ = 1550 nm.

Solution Synthesis of Sb2S3 and Na3SbS4 Solid-State Electrolyte

Sodium thioantimonate (Na3SbS4) is an attractive solid-state electrolyte for sodium-ion batteries due to its high ionic conductivity and stability in protic solvents. Herein, we describe solution-based routes for its synthesis. First, we demonstrate the synthesis of the Sb2S3 precursor via thermodynamically favorable metathesis between Na2S and SbCl3. This solution-based approach is further extended to couple the resulting Sb2S3 with Na2S for the synthesis of Na3SbS4. It is shown that ethanol is a superior solvent to water for solution-based synthesis of Na3SbS4 with respect to yield, morphology, and performance. Amorphous Sb2S3 synthesized from low-temperature metathesis produced highly crystalline Na3SbS4 with a room temperature Na+ conductivity of 0.52 mS cm−1 and low activation energy, comparable to leading values reported in the literature.

Thermoelectric performance of p-type (Bi,Sb)2Te3 incorporating amorphous Sb2S3 nanospheres

Tremendous efforts have been focusing on the improvement of p-type (Bi, Sb)2Te3-based thermoelectric materials for commercial applications. In this study, we achieve versatile interface engineering through a surface decoration of Bi0.5Sb1.5Te3 by amorphous Sb2S3 combining with spark plasma sintering, which introduces semi-coherent Sb/Bi0.5Sb1.5Te3 interfaces and dopes S into Bi0.5Sb1.5Te3. Semi-coherent Sb/Bi0.5Sb1.5Te3 interfaces strongly scatter phonons and lower energy carriers, leading to decreased thermal conductivity and increased Seebeck coefficient, while the electrical conductivity is not sacrificed due to the compromise of the slightly reduced carrier mobility by interfacial scattering and the increased carrier concentration by S doping. Benefited from the decoupled thermoelectric properties, a significantly enhanced power factor of 3345.40 μW m−1 K−2 and a low thermal conductivity of 0.78 W m−1 K−1 is obtained in Bi0.5Sb1.5Te3-0.4%Sb2S3, leading to a high peak zT of ∼ 1.31 at 330 K, which shows a 54% enhancement compared with pristine Bi0.5Sb1.5Te3. Moreover, a conversion efficiency of ∼ 7.6% can be predicted in a single leg Bi0.5Sb1.5Te3-0.4%Sb2S3-based module under a cold side temperature of 300 K and hot side temperature of 480 K. This study paves a facile amorphous Sb2S3 induced interface engineering strategy for the development of high performance (Bi,Sb)2Te3-based thermoelectric materials.

Hierarchical Sb2S3@m-Ti3C2Tx composite anode with enhanced Na-ion storage properties

Sodium-ion batteries (SIBs) have attracted much attention owing to their abundant resources, low cost, suitable energy density and low potential window. However, SIBs still suffer from poor charge transmission kinetics caused by large Na+ radius. Therefore, anode materials are considered as the key to the development of high-performance SIBs. Herein, hierarchical Sb2S3@m-Ti3C2Tx composites with Sb2S3 content of 40–60% were in-situ synthesized by a simple wet chemical method, in which amorphous spherical Sb2S3 particles with a size of 150–200 nm nucleate and grow uniformly on the surface of m-Ti3C2Tx with the formation of Ti-S bond. m-Ti3C2Tx, as a three-dimensional conductive skeleton, not only improved the electron and Na+ transportation, but also significantly inhibited the agglomeration and grain growth of Sb2S3 particles, promoted the electrolyte penetration, and effectively absorbed the volume expansion of Sb2S3 during charging and discharging cycles. As a result, the optimized 50% Sb2S3@m-Ti3C2Tx showed good rate ability and cycling performance, including a capacity of 156 mAh g−1 after 100 cycles at 0.1 A g−1 and 72 mAh g−1 after 1000 cycles at 2 A g−1 with only 0.37% attenuation per cycle. This work provided a simple and effective strategy for the design and construction of MXene-based hybrids as SIBs anode.

Superior sodium and lithium storage in strongly coupled amorphous Sb2S3 spheres and carbon nanotubes

Superior sodium and lithium storage in strongly coupled amorphous Sb2S3 spheres and carbon nanotubes

A facile two-step preparation of compact and crystalline Sb2S3 thin film for efficient solar cells

The two-step preparation of compact and crystalline Sb2S3 thin films was firstly reported using the pyrolysis of the Sb-butyldithiocarbamate complex solution in DMF. The porous and amorphous Sb2S3 thin films were successfully prepared at 170 °C for 30 min, and then can be converted to compact and crystalline Sb2S3 thin films at 200 °C for 30 min or 300 °C for 2 min. The corresponding solar cells with the architecture of FTO/TiO2 compact layer/Sb2S3/spiro-OMeTAD/Au achieved the photoelectric conversion efficiency of 4.16% at 200 °C and 5.05% at 300 °C. The two-step preparation of the compact and crystalline Sb2S3 thin films can provide the feasible approach for the fabrication of various microstructure thin film solar cells and the low preparation temperature of 200 °C was also attractive to assemble the flexible Sb2S3 thin film solar cells.

Interaction of aqueous antimony(III) with synthetic ferrous sulfide

Ferrous sulfide (FeS) is an important carrier for metal(loid)s in anoxic environments, but the effect of FeS on the behavior of Sb is poorly understood. This work investigated the interaction of Sb(III) with FeS under anoxic condition. FeS was synthesized and both equilibrium and kinetic experiments on the interaction of Sb(III) with synthesized FeS were conducted at various pH values. The final solid phases were examined by SEM, XRD, TEM, and XPS. The results showed that the uptake of Sb(III) by FeS increased as pH decreased. The kinetic experiment at pH 5 obviously showed that the temporal decrease of Sb(III)aq coincide with the partial dissolution of FeS. In contrast, both the concentrations of Sb(III)aq and FeS in the kinetic experiment at pH 9 did not vary with time. The examination of the solid phases revealed the formation of amorphous Sb2S3 in the experiments at pH 5 and 7.5. Different mechanisms were suggested to affect the interaction of Sb(III) with FeS under acidic and alkaline conditions. At pH 9, adsorption dominated in the interaction. The decrease of Sb(III)aq and the concomitant partial dissolution of FeS at pH 5 indicated the replacement of FeS by Sb2S3, which was more significant at lower pH. The replacement of FeS by Sb2S3 was a relatively slow process compared to the acidic dissolution of FeS. The result of this study helps understand the mobility of Sb in anoxic environments and may favor the remediation of Sb contamination by the use of FeS.

Optical and electrical properties of amorphous Sb2S3 thin films: Effect of the film thickness

The antimony tri-sulphide (Sb2S3) films were prepared by thermal evaporation technique. Four thicknesses (300, 521, 643 and 789 nm) were investigated. X-ray diffraction (XRD) analysis showed the amorphous structure of Sb2S3 films. Optical analyses revealed that Sb2S3 films exhibited optical energy gap between (1.98–1.16 eV) relaying on the film thickness. The films absorption coefficient was found to be higher than 2 × 104 cm−1(above its related optical energy gap) which makes these films reliable absorbers in photovoltaic applications. Optical constants were analyzed using Swanipole's method. The dark dc conductivity measurements of Sb2S3 thin films were conducted in the temperature range 298–503 K. The conduction mechanize was analyzed via Mott's variable -range hopping in three dimensions model. The correlated conductivity mechanize with increasing film thickness changed from extended states to localized states. The results revealed that both optical gap and activation energy decreased as the film thickness enhanced.

Robust formation of amorphous Sb2S3 on functionalized graphene for high-performance optoelectronic devices in the cyan-gap

Despite significant progress in the fabrication and application of semiconductor materials for optical emitters and sensors, few materials can cover the cyan-gap between 450 and 500 nm. We here introduce a robust and facile method to deposit amorphous Sb2S3 films with a bandgap of 2.8 eV. By exploiting the tunable functionality of graphene, a two-dimensional material, efficient deposition from a chemical was achieved. Ozone-generated defects in the graphene were shown to be required to enhance the morphology and quality of the material and comprehensive characterization of the seed layer and the Sb2S3 film were applied to design an optimal deposition process. The resulting material exhibits efficient carrier transport and high photodetector performance as evidenced by unprecedented responsivity and detectivity in semiconductor/graphene/glass vertical heterostructures. (112 A/W, 2.01 × 1012 Jones, respectively).

A novel and fast method to prepare a Cu-supported α-Sb2S3@CuSbS2 binder-free electrode for sodium-ion batteries.

Antimony sulfide (Sb2S3) is a promising anode material for sodium-ion batteries due to its low cost and high theoretical specific capacity. However, poor stability and a complex preparation process limit its large-scale application. Herein, we prepare a binder-free composite electrode composed of amorphous (α-) Sb2S3 and copper antimony sulfide (CuSbS2) through a simple closed-space sublimation (CSS) method. When applied as the anode in sodium-ion batteries, the α-Sb2S3@CuSbS2 electrode exhibits excellent performance with a high discharge capacity of 506.7 mA h g−1 at a current density of 50 mA g−1 after 50 cycles. The satisfactory electrochemical performance could be ascribed to the α-Sb2S3–CuSbS2 composite structure and binder-free electrode architecture, which not only retain the structural stability of the electrode but also improve the electrical conductivity. Consequently, CSS, as a scalable and environmentally friendly method, can produce a binder-free electrode in just a few minutes, demonstrating its great potential in the industrial production of sodium-ion batteries. This study may open an avenue to preparing binder-free commercial electrodes.

Amorphous Sb2S3 Anodes by Reactive Radio Frequency Magnetron Sputtering for High‐Performance Lithium‐Ion Half/Full Cells

Herein, amorphous Sb2S3 (a‐Sb2S3) anodes are prepared on 3D conductive networks by a simple reactive radio frequency (RF) magnetron sputtering process, and their application feasibility in both a lithium half cell and LiFePO4 full cell is assessed. The a‐Sb2S3 electrodes exhibit excellent cycling performance and rate capacity in the half cells, owing to the amorphous phase and 3D structure, and thus yield a high discharge capacity of 585.4 mAh g−1 at a current density of 0.2 C after 250 cycles. Moreover, the assembled a‐Sb2S3/LiFePO4 full cell can deliver 467.1 mAh g−1 at a high current density of 1000 mA g−1 even after 100 cycles. The prepared a‐Sb2S3 shows great potential to be a promising alternative anode in the application of high‐electrochemical‐performance lithium‐ion batteries.