Binary Tin Research Articles

Comparative study of binary cadmium sulfide (CdS) and tin disulfide (SnS2) thin buffer layers

Binary compound tin disulfide (SnS2) and cadmium sulfide (CdS) are the potential candidates used as a buffer layer for copper indium gallium selenide (CIGS) and copper zinc tin sulfide (CZTS) thin-film device. Herein, both compounds have been successfully prepared through simple hydrothermal (HD) and chemical bath deposition (CBD) techniques, respectively. The prepared samples were characterized by different available techniques like X-ray diffraction (XRD), atomic force microscopy (AFM), surface electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmittance electrons microscopy (TEM), UV–Visible spectroscopy and photoelectrochemical (PEC) analysis. The XRD analysis confirms the polycrystalline nature of the prepared thin films. AFM analysis showed that the SnS2 display better roughness (60 nm), grain size (75 nm) than CdS roughness (23 nm), grain size (41 nm) thin films. SEM and EDS studies revealed near stoichiometry behavior of elemental composition of the films. The optical absorption spectrum showed the direct bandgap of CdS 2.45 eV and 2.20 eV for SnS2 thin films. The PEC analysis revealed that the SnS2 thin films exhibit two times higher photoresponse (140 µA) as compare to CdS (80 µA) thin films. The SnS2 high photocurrent could be attributed to the small band gap and increase in grain size which can trap more incident light. Based on the results the SnS2 used as a buffer layer can be a good choice for an efficient photovoltaic device.

Alloy Stability of Ge1\u2212xSnx with Sn Concentrations up to 17% Utilizing Low-Temperature Molecular Beam Epitaxy

The binary alloy germanium tin has already been presented as a direct group IV semiconductor at high tin concentrations and specific strain. Therefore, it offers a promising approach for the monolithic integrated light source towards the optical on-chip communication on silicon. However, the main challenge faced by many researchers is the achievement of high tin concentrations and good crystal quality. The key issues are the lattice mismatch to silicon and germanium, as well as the limited solid solubility of tin in germanium of less than 1%. Therefore, this paper presents a systematic investigation of the epitaxial growth conditions of germanium tin with tin concentrations up to 17%. For this, we performed two growth experiments utilizing molecular beam epitaxy. In one experiment, we varied the growth temperature for the epitaxy of germanium tin with 8% tin to investigate the inter-growth temperature stability. In the second experiment, we focused on the strain-relaxation of germanium tin, depending on different tin concentrations and doping types. The results of subsequent material analysis with x-ray diffraction and scanning electron microscopy allow us to narrow the epitaxial window of germanium tin. Furthermore, we present a possible explanation for the unique relaxation mechanism of germanium tin, which is significantly different from the well-known relaxation mechanism of silicon germanium.

Computational Design of Mixed-Valence Tin Sulfides as Solar Absorbers.

Binary tin sulfides, such as SnS and SnS2, are appealing because of their simple stoichiometry and semiconducting properties and are, therefore, being pursued as potentially cost-effective materials for optoelectronic applications. The multivalency of Sn, that is, Sn(+2) and Sn(+4) allows yet more intermediate compositions, SnxSy, whose structures and properties are of interest. Sn2S3 is already under consideration as a mixed-valence semiconductor. Other intermediate compositions, for example, Sn3S4 and Sn4S5 have remained elusive, although their existences have been alluded to in literature. Here we report a comprehensive study of phase stability of the SnxSy series compounds, utilizing swarm-intelligence crystal structure search method combined with first-principles energetic calculations. We find that the stability of mixed-valence SnxSy compounds with respect to decomposition into pure-valence SnS and SnS2 is in general weaker than the SnxOy counterparts, likely due to differences in chemical bonding. Besides identifying the experimentally discovered stable phases of Sn2S3, our calculations indicate that the Sn3S4 phase is another mixed-valence composition which shows marginal stability with respect to decomposition into SnS and SnS2. Other studied compositions may be metastable under ambient conditions, with slightly positive formation enthalpies. We find two structures of Sn3S4 having comparably low energies, both of which feature one-dimensional chain-like fragments obtained by breaking up the edge-connected octahedral layers of SnS2. Both structures indicate lattice phonon stability and one shows quasi-direct band gap with a calculated value of 1.43 eV, ideal for solar absorbers. A further analysis of the composition-structure-property relationship supports the notion that low-dimensional Sn-S motifs and van der Waals interaction may lead to diverse structure types and chemical compositions, having functional properties that are yet to be identified in the SnxSy series with mixed valency.

Gain-Assisted Transition Metal Ternary Nitrides (Ti1−xZrxN) Core–Shell Based Sensing of Waterborne Bacteria in Drinking Water

We propose gain-assisted Ti1 − xZrxN-based multilayered core–shell nanoparticles (MCSNPs) as refractive index (RI) sensor for real-time and label-free detection of waterborne bacteria. RI sensor designs optimized for diseases caused by pathogen Escherichia coli (E. coli), Serratia marcescens (S. marcescens), and Mierococcus lysodeikticus (M. lysodeikticus) are presented. Mie theory–based analysis shows that the precise incorporation of optical gain can compensate plasmonic losses at resonant wavelength and enhance sensor’s figure of merit (FOM) for bacteria detection up to ~ 106–107. The use of Ti1 − xZrxN ternary alloy as plasmonic material is advantageous as (I) Ti1 − xZrxN offers an alternative to the conventional plasmonic materials (e.g., Au, Ag, Cu, etc.); (II) specific Ti/Zr fractions in ternary Ti1 − xZrxN reduces the critical gain requirement compared to binary TiN; and (III) spectrum can be fine-tuned by controlling Ti/Zr fraction. The present work can led to the development of ultrasensitive plasmonic sensors capable of single bacteria detection as well as level of concentration of bacteria in water.

Structure of tin phosphate glasses by neutron and X-ray diffraction

Abstract Neutron and X-ray diffraction experiments with large ranges of scattering vector, up to Qmax of 400 nm−1 and 250 nm−1, respectively, were performed on (SnO)x(P2O5)1-x glasses with 0.5 ≤ x ≤ 0.7, and the structural parameters of the P O and Sn O polyhedra were determined. The fraction of P–NBO (non-bridging oxygen) bonds increases systematically at the expense of the P–BO (bridging oxygen) bonds with SnO additions. The Sn O coordination number decreases in a predictable way from four at the metaphosphate composition (x = 0.5) to about three at the diphosphate composition (x = 0.67). The structural units are assumed to be SnO4 trigonal bipyramids and SnO3 trigonal pyramids with the lone-pair of Sn(II) electrons occupying one of the corners, similar to those in related crystal structures. For all glasses up to x = 0.67, the SnOz pyramids and PO4 tetrahedra form a continuous network with P O P and P O Sn bonds and the Sn O polyhedra do not share oxygen neighbors. From comparisons of the compositional dependences of the Sn O and Zn O coordination numbers and the respective number densities of atoms in the binary tin and zinc phosphate glasses, it is presumed that the Sn O coordination increases further with NSnO > 4 in the ultraphosphate range (x

Semi-Empirical Force-Field Model for the Ti1-xAlxN (0 ≤ x ≤ 1) System.

We present a modified embedded atom method (MEAM) semi-empirical force-field model for the Ti1−xAlxN (0 ≤ x ≤ 1) alloy system. The MEAM parameters, determined via an adaptive simulated-annealing (ASA) minimization scheme, optimize the model’s predictions with respect to 0 K equilibrium volumes, elastic constants, cohesive energies, enthalpies of mixing, and point-defect formation energies, for a set of ≈40 elemental, binary, and ternary Ti-Al-N structures and configurations. Subsequently, the reliability of the model is thoroughly verified against known finite-temperature thermodynamic and kinetic properties of key binary Ti-N and Al-N phases, as well as properties of Ti1−xAlxN (0 < x < 1) alloys. The successful outcome of the validation underscores the transferability of our model, opening the way for large-scale molecular dynamics simulations of, e.g., phase evolution, interfacial processes, and mechanical response in Ti-Al-N-based alloys, superlattices, and nanostructures.

Ternary and quarternary TiBN and TiBCN nanocomposite coatings deposited by arc ion plating

Binary TiN monolayer coating cannot meet the demands of the industrial application. a route for improving its performance is the addition of new element: silicon, boron or carbon. Therefore the main objective of this work is the preparation of TiBN and TiBCN coatings with a nanocomposite structure offering a higher micro-hardness as well as an improved wear resistance. Arc ion plating was used for the deposition of the TiBN and TiBCN coatings on Si (100) and cemented carbide substrates. TiBN nanocomposites coatings was deposited using TiB2 composite target in pure N2 whereas for TiBCN coatings was in mixed C2H2 and N2. The components, microstructure and mechanical properties behavior of the nanocomposite coatings were investigated. TiBN coatings consisted of the crystalline phases TiN, TiB2 and amorphous BN. A maximum micro-hardness of about 3160 HV was observed at a 0.5 Pa N2 pressure while the micro-hardness correlates well with N2 pressure. TiBCN coatings prepared with the N2 and C2H2 process exhibit a nanocomposite structure of nanocrystalline TiN and TiB2, morphous C, CN and BN. Compared to TiBN, lower micro-hardness of the TiBCN coatings down to 1761 HV was measured for at 1/2 gas flow ratio of C2H2 and N2. For grinding material cemented carbide, the friction coefficient of TiBN coating was nearly 0.4 while the friction coefficient of TiBCN coatings was lower 0.2 with the increasing of C2H2 and N2 flow ratio.

Low Interface Energies Tune the Electrochemical Reversibility of Tin Oxide Composite Nanoframes as Lithium-Ion Battery Anodes.

The conversion reaction of lithia can push up the capacity limit of tin oxide-based anodes. However, the poor reversibility limits the practical applications of lithia in lithium-ion batteries. The latest reports indicate that the reversibility of lithia has been appropriately promoted by compositing tin oxide with transition metals. The underlying mechanism is not revealed. To design better anodes, we studied the nanostructured metal/Li2O interfaces through atomic-scale modeling and proposed a porous nanoframe structure of Mn/Sn binary oxides. The first-principles calculation implied that because of a low interface energy of metal/Li2O, Mn forms smaller particles in lithia than Sn. Ultrafine Mn nanoparticles surround Sn and suppress the coarsening of Sn particles. Such a composite design and the resultant interfaces significantly enhance the reversible Li-ion storage capabilities of tin oxides. The synthesized nanoframes of manganese tin oxides exhibit an initial capacity of 1620.6 mA h g-1 at 0.05 A g-1. Even after 1000 cycles, the nanoframe anode could deliver a capacity of 547.3 mA h g-1 at 2 A g-1. In general, we demonstrated a strategy of nanostructuring interfaces with low interface energy to enhance the Li-ion storage capability of binary tin oxides and revealed the mechanism of property enhancement, which might be applied to analyze other tin oxide composites.

Structural investigations of SnS1-xSex solid solution synthesized from chalcogeno-carboxylate complexes of organo-tin by colloidal and solvent-less routes.

Tin chalcogenides are important semiconducting materials due to their non-toxic nature, cost effectiveness and layered structure. In this study, a facile synthetic route has been employed for the synthesis of a bis(selenobenzoato)dibutyltin(iv) complex, and used along with the bis(thiobenzoato)dibutyltin(iv) complex, as single source precursors, to prepare binary tin chalcogenides and their solid solution (SnS1-xSex) in the entire range. The synthesis of the solid solution was carried out by colloidal and melt methods. The comparative analysis of the solid solution obtained from both routes indicates that the colloidal method provides superior control over composition. The UV-Vis-NIR analysis showed a gradual change in the band gap, while moving from SnS to SnSe.

Facile Bulk Synthesis of π-Cubic SnS.

The cubic modification of binary tin sulfide (SnS) has gained significant interest as an earth-abundant, low-toxicity solar absorber material with a band gap close to the optimal value for the conversion of sunlight. We herein report a simple synthesis for the metastable material, which will allow more elaborate characterization methods to be used on this material, and present a full powder refinement of the material along with some preliminary results on the optical and thermal stability properties.

Syntheses and Properties of Gold-Organotin Sulfide Clusters.

We report that reactions of the binary organotin sulfide cluster [(R1Sn)3S4]Cl [A; R1 = CMe2CH2C(O)Me] with gold(I) phosphane complexes yield discrete ternary complexes [(R1Sn)2(AuPMe3)2S4] (1) and [(R2Sn)2(AuPMe3)2S4] [2; R2 = CMe2CH2C(NNH2)Me], which are related to recently published complexes [(R1,2Sn)2(AuPPh3)2S4] (B and C). Further, we present a binary tin sulfide cluster that cocrystallizes with a structure-directing salt of a gold phosphane complex in [Au(dppe)2][(R3Sn)4S6Cl] [3; R3 = CMe2CH2C(NNHPh)Me]. The nature of the product depends on the choice of the phosphane ligand as well as the addition of hydrazine hydrate or phenylhydrazine. Additionally, we report on the photophysical properties of 1, 2, B, and C, which indicate that the different phosphane ligands only have a slight influence on the optical responses. The structure, however, has a significant impact on the luminescence efficiency.

Mechanism of Tin Oxidation and Stabilization by Lead Substitution in Tin Halide Perovskites

The recent development of efficient binary tin- and lead-based metal halide perovskite solar cells has enabled the development of all-perovskite tandem solar cells, which offer a unique opportunity to deliver high performance at low cost. Tin halide perovskites, however, are prone to oxidation, where the Sn2+ cations oxidize to Sn4+ upon air exposure. Here, we identify reaction products and elucidate the oxidation mechanism of both ASnI3 and ASn0.5Pb0.5I3 (where A can be made of methylammonium, formamidinium, cesium, or a combination of these) perovskites and find that substituting lead onto the B site fundamentally changes the oxidation mechanism of tin-based metal halide perovskites to make them more stable than would be expected by simply considering the decrease in tin content. This work provides guidelines for developing stable small band gap materials that could be used in all-perovskite tandems.

Study of the properties and structure of binary tin silicate glasses with zero photoelastic constant

Sn-containing silicate glasses with zero photoelastic constant (PEC) can potentially substitute zero-PEC Pb-containing glasses as optical fiber current sensor components based on the Faraday effect. These compounds allow monitoring of the electric power by measuring the electric current in high-voltage conductors operated with a 1550-nm light. The toxicity of Pb in these glasses still remains an important issue. However, replacing Pb in the sensors while minimizing the PEC of the resulting device would represent a significant breakthrough. We report a 43.5SnO–56.5SiO2 glass in molar% with zero PEC of + 0.01 × 10−12 Pa−1 observed with a wavelength of 632.8 nm.

Electronic Structure and Defect Physics of Tin Sulfides: SnS,Sn2S3, andSnS2

Lately binary tin sulfides, being composed of inexpensive earth-abundant elements, have come under intense scrutiny for applications spanning photovoltaics, thermoelectrics, valleytronics, batteries, and photocatalysis. The authors use first-principles methods to examine these materials' point defects, which can play crucial roles in electronic applications. This comprehensive study expands the technological horizons for the tin sulfides, particularly the less-studied Sn${}_{2}$S${}_{3}$, which is predicted to support either $p$-type or $n$-type doping---a coveted property.

ChemInform Abstract: Recent Developments in p‐Type Oxide Semiconductor Materials and Devices

AbstractReview: 400 refs.

Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures.

Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non-ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here, we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin film experiments indicate that this novel material is N-deficient SnN with tin in the mixed ii/iv valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. This observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn3N4 spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of metastable materials. In addition to reporting on the discovery of the simple binary SnN compound, this paper illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials.

Recent Developments in p-Type Oxide Semiconductor Materials and Devices.

The development of transparent p-type oxide semiconductors with good performance may be a true enabler for a variety of applications where transparency, power efficiency, and greater circuit complexity are needed. Such applications include transparent electronics, displays, sensors, photovoltaics, memristors, and electrochromics. Hence, here, recent developments in materials and devices based on p-type oxide semiconductors are reviewed, including ternary Cu-bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. The crystal and electronic structures of these materials are discussed, along with approaches to enhance valence-band dispersion to reduce effective mass and increase mobility. Strategies to reduce interfacial defects, off-state current, and material instability are suggested. Furthermore, it is shown that promising progress has been made in the performance of various types of devices based on p-type oxides. Several innovative approaches exist to fabricate transparent complementary metal oxide semiconductor (CMOS) devices, including novel device fabrication schemes and utilization of surface chemistry effects, resulting in good inverter gains. However, despite recent developments, p-type oxides still lag in performance behind their n-type counterparts, which have entered volume production in the display market. Recent successes along with the hurdles that stand in the way of commercial success of p-type oxide semiconductors are presented.

Vapor–liquid phase equilibria of binary tin–antimony system in vacuum distillation: Experimental investigation and calculation

Vacuum distillation experiments were conducted for tin-antimony alloy (Sn–Sb alloy) under the system pressure of 5 Pa. The content of Sb (mole fraction) in crude Sn, viz., xSb was reduced from 0.5000 to 0.0619 in a single stage distillation process under the condition of residual pressure of 5–10 Pa, distillation temperature of 1373 K and distillation time of 60 min. The activity coefficients of components of Sn–Sb alloy were calculated by using the molecular interaction volume model (MIVM), and the calculated average relative deviation and the average standard deviation were ±0.00039 and ± 0.173%, respectively for both Sn and Sb. The vapor–liquid equilibrium (VLE) phase diagrams, including the temperature-composition (T-x) and pressure-composition (p-x) diagrams of Sn–Sb alloy in vacuum distillation were calculated based on VLE theory and the MIVM. A reasonable agreement between the calculated results and the experimental data indicates that VLE phase diagrams obtained by this method are reliable. The VLE phase diagrams of alloys will provide an effective and convenient way for the designing of the process parameters of industrial production of vacuum metallurgy, and for the prediction of the needed product component dependence of temperature and pressure during the process of vacuum distillation.

Solvent-molecule-mediated manipulation of crystalline grains for efficient planar binary lead and tin triiodide perovskite solar cells.

Binary lead and tin perovskites offer the benefits of narrower band gaps for broader adsorption of solar spectrum and better charge transport for higher photocurrent density. Here, we report the growth of large, smooth crystalline grains of bianry lead and tin triiodide perovskite films via a two-step solution process with thermal plus solvent vapor-assisted thermal annealing. The crystalline SnxPb1-xI2 films formed in the first step served as the templates for the formation of crystalline CH3NH3SnxPb1-xI3 films during the second step interdiffusion of methylammonium iodide (MAI). Followed by dimethylsulfoxide (DMSO) vapor-assisted thermal annealing, small, faceted perovskite grains grew into large, smooth grains via the possible mechanism involving bond breaking and reforming mediated by DMSO solvent molecules. The absorption onset was extended to 950 and 1010 nm for the CH3NH3SnxPb1-xI3 perovskites with x = 0.1 and 0.25, respectively. The highest PCE of 10.25% was achieved from the planar perovskite solar cell with the CH3NH3Sn0.1Pb0.9I3 layer prepared via the thermal plus DMSO vapor-assisted thermal annealing. This research provides a way to control and manipulate film morphology, grain size, and especially the distribution of metal cations in binary metal perovskite layers, which opens an avenue to grow perovskite materials with desired properties to enhance device performance.

Effects of phase stability, lattice ordering, and electron density on plastic deformation in cubic TiWN pseudobinary transition-metal nitride alloys

We carry out density functional theory calculations to compare the energetics of layer glide, as well as stress vs. strain curves, for cubic Ti0.5W0.5N pseudobinary alloys and reference B1-structure TiN. Irrespective of the degree of ordering on the metal sublattice, the hardness and stiffness of Ti0.5W0.5N, as estimated by stress–strain results and resistance to layer glide, are comparable to that of the parent binary TiN, while ductility is considerably enhanced. After an initial elastic response to an applied load, the pseudobinary alloy deforms plastically, thus releasing accumulated mechanical stress. In contrast, stress continues to increase linearly with strain in TiN. Layer glide in Ti0.5W0.5N is promoted by a high valence-electron concentration which enables the formation of strong metallic bonds within the slip direction upon deformation. [111]-oriented Ti0.5W0.5N layers characterized by high local metal-sublattice ordering exhibit low resistance to slip along <110> directions due to energetically favored formation of (111) hexagonal stacking faults. This is consistent with the positive formation energy of <111>-ordered Ti0.5W0.5N with respect to mixing of cubic-B1 TiN and hexagonal WC-structure WN. In the cubic pseudobinary alloy, slip occurs parallel, as well as orthogonal, to the resolved applied stress at the interface between layers with the lowest friction. We suggest that analogous structural metastability (mixing cubic and hexagonal TM nitride binary phases) and electronic (high valence electron concentration) effects are responsible for the enhanced toughness recently demonstrated experimentally for cubic single-crystal pseudobinary V0.5W0.5N and V0.5Mo0.5N epitaxial layers.