Lead-free perovskite layers may provide a good alternative to the commonly used lead-halide-based perovskite absorber layers in photovoltaics. Energy level alignment of the active semiconductor with contact layers is a key factor in device performance. Kelvin probe force microscopy was used during vapor deposition of C60 onto formamidinium tin iodide to investigate contact formation with detailed local resolution of these materials that are significant for photovoltaic cells. Significant differences dependent on the growth rate of C60 were detected. Sufficiently high deposition rates were essential to reach compact C60 films needed for good contact. A space charge layer larger than 90 nm within the C60 layer was established without indication of interfacial dipoles. The present analysis gives a clear indication of a well-functioning contact of fullerenes to formamidinium tin iodide that is suitable for the use in photovoltaic devices provided that thin compact fullerene films are formed.

Irinarassite, Ca3Sn2SiAl2O12, a new mineral species of the garnet supergroup was discovered in metasomatically altered carbonate-silicate xenoliths in ignimbrites of the Upper Chegem Caldera, Northern Caucasus, Kabardino-Balkaria, Russia. It occurs as small zones and irregular spots in kimzeyite-kerimasite or rarely as single crystals not exceeding 10 μm in size, within complex pseudomorphs after zircon. Lakargiite, tazheranite, baddeleyite, kerimasite, kimzeyite, baghdadite and rarely magnesioferrite are associated with irinarassite in the pseudomorphs which are confined to larnite-cuspidine zones immediately adjoining the ignimbrite. Larnite, cuspidine, rondorfite, fluor- and hydroxylellestadite, fluorite and secondary minerals such as ettringite, hillebrandite and bultfonteinite are associated with irinarassite. Irinarassite is pale brown to yellow colour. The mineral is characterized by the absence of cleavage and by an irregular fracture. The calculated density is 4.3 g cm–1. The mineral is isotropic with a calculated refractive index of 1.9. The empirical crystal chemical formula of irinarassite from the holotype specimen is as follows (Ca2.965Fe2+0.035)Σ3(Sn1.016Zr0.410Ti0.262Sb5+0.237Fe2+0.035U6+0.017Sc0.014Hf0.006Nb0.004)Σ2.001(Al1.386Fe3+0.804Si0.446Ti4+0.364)Σ3O12. Electron backscatter diffraction patterns of irinarassite are fitted to the garnet model with a = 12.50(3) Å with excellent MAD (mean angular deviation) = 0.16°. The Raman spectrum of irinarassite is analogous to those of kerimasite and other Zr-Sn-garnets of the schorlomite and bitikleite groups.

In this work, a very high, locally applied electric field was used to induce whisker nucleation on an Sn film. The field was generated by using a conductive AFM tip and applying a voltage bias between the sample and the conductive cantilever. The tip-sample separation distance was thus controllable, and any dielectric breakdown could be avoided. At locations where the AFM tip was positioned for an extended period, minuscule whiskers were observed, whose growth direction matched vertical orientation of the field.

This study reports a high-performance tin (Sn)-coated vertically aligned carbon nanofiber array anode for lithium-ion batteries. The array electrodes have been prepared by coaxial sputter-coating of tin (Sn) shells on vertically aligned carbon nanofiber (VACNF) cores. The robust brush-like highly conductive VACNFs effectively connect high-capacity Sn shells for lithium-ion storage. A high specific capacity of 815 mAh g-1 of Sn was obtained at C/20 rate, reaching toward the maximum value of Sn. However, the electrode shows poor cycling performance with conventional LiPF6 based organic electrolyte. The addition of fluoroethylene carbonate (FEC) improve the performance significantly and the Sn-coated VACNFs anode shows stable cycling performance. The Sn-coated VACNF array anodes exhibit outstanding capacity retention in the half-cell tests with electrolyte containing 10 wt.% FEC and could deliver a reversible capacity of 480 mAh g-1 after 50 cycles at C/3 rate.

Antimony doped tin oxide (ATO) is an ideal material for thermal insulation. To obtain the stable performance of ATO nanodispersions and measure the transparent and thermal insulation properties of the ATO coatings, we investigated how a dispersant and sand milling affect the stability of ATO dispersion, which has come to the results that adding an appropriate dispersant and sand milling for 2.0 h were beneficial to the ATO dispersion. We characterized the morphology, nanostructure, particle size distribution, zeta potential, and optical properties of the ATO dispersions by a transmission electron microscope (TEM), a laser particle size analyzer, and a spectrometer. The results show that the average particle size of the dispersions is about 50 nm and their absolute values of all zeta potentials are more than 40 mV. We coated the thermal insulation water-based coatings on quartz glasses by spin coating method, the effect of thermal insulation is evident with the increase of the ATO content, and there exists approximately 10 °C difference between the ATO sample and blank sample with the condition for maintaining high transmittance of visual light.

Gas detecting and sensing is a largely studied field of knowledge, but total understanding is not yet achieved and the ideal device is still far in the future. Many experimental efforts have been devoted to find the minimum optimal temperature and operational conditions for SnO2 to sense hydrocarbons; different methods to build gas-detecting devices keep being developed all around the world, from paste-based bulk devices to nanostructured thick and thin films, but little effort has been aim to characterize the reactions by calculating their related enthalpies. Computational methods have been widely used to characterize, understand and model many physicochemical interactions. In this regard, three main courses can be followed: Ab initio (first principles of quantum mechanics), DFT (Density Functional Theory) and MD (Molecular Dynamics) simulation. In this research, DFT modelling tool is employed to understand and characterize the gas-sensing reactions of Tin Oxide when exposed to an atmosphere with Methane. In CASTEP, a robust DFT module of the Materials Studio suite, one SnO2 (110) crystal plane is exposed to CH4 and the structure is optimized many times for each possible step of the reaction, recording the energies related with each optimization stage, in sum giving us the Transition State (TS) of the reaction. Based on the data, a promising reaction-path is proposed and analyzed for the (110) surface.

Two-dimensional group IV layers beyond graphene, as silicene, germanene and the Sn-based stanene, have been recently synthesized by molecular beam epitaxy. Density Functional Theyory (DFT) calculations predict low-buckled structures for these 2D nanosheets, with a hexagonal honeycomb conformation, typical of the graphene-like surfaces. The buckling parameter δ increases from Si to Sn-based layers, with a maximum predicted of 0.92 Å for stanene. High-buckled structures for these materials resulted to be unstable. We have previously shown that for silicene and germanene, the origin of the buckled structure resides on the pseudo Jahn-Teller puckering distortion, resulting from non-adiabatic effects. It has been shown that hexagermabenzene, the single hexagonal unit of germanene, is subject to a strong vibronic coupling whose origin is the pseudo Jahn-Teller effect. This coupling resulted to be around ten times larger than the one obtained for hexasilabenzene. For stanene, an additional effect needs to be considered to understand the origin of buckling: the spin-orbit coupling (SOC). This SOC contributes to open an electronic band gap, enabling the use of these layers as nanoelectronic components. In this work, we present an analysis based on DFT in the Zeroth-Order Regular Approximation (ZORA) for both scalar relativistic and spin-orbit versions that quantify the influence of the spin-orbit coupling in the puckering of Sn6H6. Also, under the linear vibronic coupling model between the ground and the lowest excited states, we present the pseudo Jahn-Teller contribution. The scalar ZORA approximation is used to perform time-dependent DFT calculations to incorporate the low-energy excitations contributions. Our model leads to the determination of the coupling constants and predicts simultaneously the Adiabatic Potential Energy Surface behavior for the ground and excited states around the maximum symmetry point. These values allow us to compare the Jahn-Teller relevance in buckling with the other group IV layers.

This paper discusses a pulse electroplating method for developing tin (Sn)-decorated gas diffusion electrodes (GDEs) for the electrochemical conversion of carbon dioxide (CO2) to formate. The pulse-plated Sn electrodes achieved current densities up to 388 mA/cm2, more than two-fold greater than conventionally prepared electrodes (150 mA/cm2), both at a formate selectivity of 80%. Optical and microscopic analyses indicate improvements in deposition parameters could further enhance performance by reducing the catalyst particle size.

Tin(Sn) and its alloys have been attracting attentions as a negative electrodematerial for sodium-ion secondary batteries with high theoretical capacity(Na15Sn4, ca. 847 mAh/g) and highelectromotiveforce. There still remains the issue as regards the dischargecapacity decrease with increasing the number of cycles. In order to improvecycle performance, there are many studies such as using Sn-Ni alloy, however,using Sn based alloy as negative electrode materials and it suffer from thedisadvantage of lowering of discharge capacity. In this study, a depositionprocess for making Sn film which consists of amorphous structure for negativeelectrode of sodium ion secondary batteries utilizing electordeposition fromaqueous bath was developed. The effect of additives on the surface morphologyand microstructure of Sn film was investigated. Furthermore, we evaluated theeffect of amorphous structure in the Sn film on cycle performance of the Snnegative electrode. Sn film has a good cycle characteristic (>50cycles) and discharge capacity (> 400 mAh/g). Amorphous structure inthe Sn film showed a microscopic effect on the volume change by sodiation anddesodiation.

This work presents a preliminary experimental study on the possibility to initiate growth of whiskers on the surfaces of some technologically important metals utilizing the enhanced electric field of surface plasmon polaritons (SPPs). The results provide evidence that a relatively high concentration of what appear to be whisker nuclei form in the region where SPPs were excited, whereas no such changes are observed on the untreated surface.

Transparent conducting thin-films of SnO2: F were grown on preheated glass, Al2O3 coated glass, and quartz substrates by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl4) and ammonium fluoride (NH4F) dissolved in a mixture of deionized water and organic solvents were used as precursors. The preheated substrate temperature was varied between 440 and 500 °C. High quality SnO2:F films were grown at all the substrate temperatures studied. The resulting typical film thickness was 250 nm. X-ray diffraction shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93% throughout the wavelength range 400 to 1000 nm. The lowest electrical resistivity achieved was 6 × 10-4 Ω-cm. The Hall measurements showed that the film is an n-type semiconductor, with carrier mobility of 8.3 cm2/V-s, and carrier concentration of 1 × 1021 cm-3. The direct bandgap was determined to be 4.0 eV from the transmittance spectrum.

Tin oxide aerogels were synthesized using the epoxide-assisted technique and characterized with X-ray diffraction, diffusive reflectance spectroscopy, particle-induced X-ray emission and scanning electron microscopy. Our results indicate that the material is electrically semi-insulating as the result of oxygen vacancies that appear as fixed charges at the bottom of the conduction band. A modification of the technique with the addition of hydrogen peroxide is proposed to reduce the levels of defects and enhance the optical transparency of the material.

BaTiO3–SnO solid solutions have been investigated from the viewpoints of synthesis and Sn ion valence. First-principles calculations show that the solution energy of Sn2+ into the Ba sites in BaTiO3 is less than that into the Ti sites under high pressure. The BaTiO3–SnO solid solutions have been synthesized under high pressure (∼20 GPa) and temperatures using a laser-heated diamond anvil cell. The synthesized materials have been characterized using x-ray diffractometry, scanning transmission electron microscopy, and energy-dispersive x-ray spectroscopy. It is found from these various methods that we have successfully synthesized uniform solid solutions of BaTiO3–SnO. Furthermore, it is also clarified by the Sn L3-edge electron energy loss spectra measurements that the valences of the Sn ions in the BaTiO3–SnO solid solution are 2+. These results indicate that the Sn2+ ions are substituted into the Ba sites, according to the ion size. Consequently, the Sn ions can be substituted into the Ba sites of the shrinking BaTiO3 lattice under high pressure, which is similar to the Ca and Sn co-substitution into Ba sites under ambient pressure as reported previously.

We investigated how changes in the method of supplying Sn and Fe carbon nanocoil (CNC) catalysts affected the results of chemical vapor deposition. The Sn/Fe catalysts were supplied using the following four materials: a thin Sn film, a drop-coated solution of Fe2O3, tetramethyltin (TMT) vapor, and ferrocene vapor. The CNC purity was evaluated using scanning electron microscopy. The CNC purity in the overall carbon deposit was also evaluated by analyzing the cross-section of the deposit. The CNC purity averaged over the overall carbon deposit was increased 1.5-fold by the TMT supply. We obtained a maximum CNC purity of 72% using a combination of TMT and ferrocene vapors, with Sn/Fe deposition on the substrate. Energy-dispersive x-ray spectroscopy analysis of the catalyst nanoparticles in the tips of the CNCs and carbon nanofibers (CNFs) revealed that there was a large difference in the Sn/Fe molar ratios for the angular- and round-type CNFs.

As Si-transistor technology advances beyond the 10 nm node, the device research community is increasingly looking into the possibility of replacing Si with novel, high mobility materials as the transistor channel. Among several possible candidate materials, germanium and germanium-tin alloys (GeSn) have emerged as strong contenders for the next generation of complementary metal oxide semiconductor (CMOS) transistors. This article presents a comprehensive overview of the state of the art in Ge and GeSn transistor research. We address several key material challenges involved in fabricating high-performance Ge/GeSn-based CMOS transistors, such as gate stack formation and achieving low-resistance contacts to transistor source/drain regions. Using Ge/GeSn as channel materials, we present a FinFET-based, Si-compatible CMOS solution for device dimensions expected in the 7 nm technology node, discuss the practical challenges involved in realizing this design, and highlight directions for future research.

SnO2-based varistors are strong candidates to replace the ZnO-based varistors due to ordering fewer additives to improve its electrical behavior as well as by showing similar nonlinear characteristics of ZnO varistors. In this work, SnO2-nanoparticles based-varistors with addition of 1.0 %mol of ZnO and 0.05 %mol of Nb2O5 were synthesized by chemical route. SnO2.ZnO.Nb2O5-films with 5 μm of thickness were obtained by electrophoretic deposition (EPD) of the nanoparticles on Si/Pt substrate from alcoholic suspension of SnO2-based powder. The sintering step was carried out in a microwave oven at 1000 °C for 40 minutes. Then, Cr3+ ions were deposited on the films surface by EPD after the sintering step. Each sample was submitted to different thermal treatments to improve the varistor behavior by diffusion of ions in the samples. The films showed a nonlinear coefficient (α) greater than 9, breakdown voltage (VR) around 60 V, low leakage current (IF ≈ 10-6 A), height potential barrier above 0.5 eV and grain boundary resistivity upward of 107 Ω.cm.

In this study, the formation of Ni-(GeSn)x on strained and relaxed Ge1−xSnx (0.01≤x≤ 0.03) nanowires in contact areas has been investigated. The epi-layers were grown at different temperatures (290 to 380°C) by RPCVD technique. The strain in GeSn layers tailored through carefully chosen of growth parameters and virtual substrate. The nanowires were fabricated through both I-line and dry-etching. 15 nm Ni was deposited either on the contact areas or whole length of nanowires. The wires went through rapid thermal annealing at intervals of 360 to 550°C for 30s in N2 ambient. The results show the thermal stability and amount of particular phases were strain-dependent. The formation of Ni-GeSn was eased when GeSn layers were strain-free. When the Sn content is high the epi-layers suffer from Sn segregation. The Sn-rich surface impedes remarkably the Ni diffusion. The electrical conductivity measurement of nanowires shows low resistivity and Ohmic contact are obtained for Ni-GeSn.

In the present work, a comparative study is attempted, dealing with the influence of the grain size distribution on the microstructure and the free carrier concentration in Mg2SnXSi1-X (x=0.2) ternary compounds doped with Sb. Structural in-homogeneities were monitored by using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) as well as Fourier transform infrared spectroscopy (FTIR) in the reflectivity mode.

Transparent conducting cadmium tin oxide (CTO) thin films were obtained from a mixture of CdO and SnO2 precursor solutions by the dip-coating sol-gel technique. The thin films studied in this work were made with 7 coats (∼200 nm) on corning glass and quartz substrates. Each coating was deposited at a withdrawal speed of 2 cm/min, dried at 100°C for 1 hour and then sintered at 550°C for 1 hour in air. In order to decrease the resistivity values of the films, these were annealed in a vacuum atmosphere and another set of films were annealed in an Ar/CdS atmosphere. The annealing temperatures (Ta) were 450°C, 500°C and 550°C, as well as 600°C and 650°C, when corning glass and quartz substrates were used, respectively. X-Ray diffraction (XRD) patterns of the films annealed in a vacuum showed that there is only the presence of CTO crystals for 450°C≤ Ta ≤ 600°C and CTO+SnO2 crystals for Ta=650°C. The films annealed in Ar/CdS atmosphere were only constituted of CTO crystals independent of the Ta. The minimum resistivity value obtained was ∼4 x 10-4 Ωcm (Rsheet= 20 Ω/□) for the films deposited on quartz and annealed at Ta=600°C under an Ar/CdS atmosphere. The films deposited on quartz showed the higher optical transmission (∼90%) with respect to the films deposited on corning glass substrates (∼85%) in the Uv-vis region. For their optical and electrical characteristics, these films are good candidates as transparent electrodes in solar cells.

Carbon supported Pt-SnO2 electrocatalysts with different Sn/Pt molar ratios were prepared by an electron beam irradiation method. Dissolved gas conditions in the vials irradiated with electron beam were controlled to air or Ar. The results of the material analyses showed that both Pt and SnO2 were immobilized onto carbon support in all catalysts. Bubbling Ar to the precursor solution led to steady change of metal contents in response to the precursor concentrations. The ethanol oxidation activity plotted against Sn/Pt ratio behaved differently with dissolved gas condition of the vial. This difference is discussed with supposed existing state of SnO2 in connection with the reduction process of Pt and Sn.