High Concentrations Of Tin Research Articles

Green-assisted synthesis of highly defective nanostructured Fe-doped SnO2: Magnetic and photocatalytic properties evaluation

Here we present a comprehensive characterization of the properties of undoped and Fe-doped SnO2 nanoparticles prepared with Syzygium cumini leaves extract. The phytochemicals present in the leaves extract act as cation chelating and capping of the nanoparticles. It is observed a relative high concentration of tin (up to 10 %) and oxygen (up to 5%) vacancies promoted by surface adsorbed OH− and by Fe-doping, respectively. The magnetic characterization reveals a ferromagnetic with a saturation monetization up to 20×10−3 emu/g for the higher defective and Fe-doped sample. This behavior associated mainly to tin vacancies for the undoped samples, and to the formation of bound magnetic polarons between the incorporated Fe and the oxygen vacancies for the doped samples. Oxygen vacancies and incorporated Fe improve the SnO2 photocatalytic efficiency in the visible range of the electromagnetic spectrum by decreasing the SnO2 effective bandgap from 3.6 eV for the undoped SnO2 sample to only 1.9 eV for the Fe-doped SnO2 sample, and by acting as electron-trapping centers increasing the system quantum efficiency. Due to the ferromagnetic behavior of the studied samples, it was also considered the effect of spin-dependent processes in the observed photocatalytic improvement. Our results highlight the key role of defect engineering strategies to optimize the physical and chemical properties of semiconductor oxides for application in the development of spintronic and quantum information devices, and in systems devoted to wastewater purification through advanced oxidation processes.

Analysis of structural and electrical properties of Sn modified Ca0.6Sr0.4TiO3 ceramics

In this study, we synthesized Ca0.6Sr0.4Ti1-xSnxO3 ceramics using the solid-state reaction technique, varying the Sn compositions from x = 0.0 to 0.08. X-ray diffraction analysis revealed a slight modification in the crystallographic structure of calcium strontium titanate (CST) as the Sn content increased, while confirming the formation of single-phase ceramics. Parameters such as crystallite size, lattice strain, stacking fault, and dislocation density were estimated based on the XRD data. Crystallite size generally increased with higher tin concentrations, except for x = 0.08 where a decrease was observed. The FTIR spectra exhibited a broad band, and deconvolution using a Gaussian distribution was employed to identify structural units. Density measurements demonstrated densification with increasing Sn content. The activation energy values increased from 0.76 eV for undoped CST to 0.95 eV for x = 0.06, except for x = 0.08, which measured 0.89 eV, indicating the role of Sn in modifying the structure. Activation energy was determined through linear fitting of experimental data, revealing that the reciprocal temperature dependence of DC conductivity followed Arrhenius behaviour. These findings contribute novel insights into the synthesis and characterization of Ca0.6Sr0.4Ti1-xSnxO3 ceramics, highlighting the impact of Sn on the structural and electrical properties of CST.

Stability of silicon–tin alloyed nanocrystals with high tin concentration synthesized by femtosecond laser plasma in liquid media

Nanocrystals have a great potential for future materials with tunable bandgap, due to their optical properties that are related with the material used, their sizes and their surface termination. Here, we concentrate on the silicon–tin alloy for photovoltaic applications due to their bandgap, lower than bulk Si, and also the possibility to activate direct band to band transition for high tin concentration. We synthesized silicon–tin alloy nanocrystals (SiSn-NCs) with diameter of about 2–3 nm by confined plasma technique employing a femtosecond laser irradiation on amorphous silicon–tin substrate submerged in liquid media. The tin concentration is estimated to be sim 17%, being the highest Sn concentration for SiSn-NCs reported so far. Our SiSn-NCs have a well-defined zinc-blend structure and, contrary to pure tin NCs, also an excellent thermal stability comparable to highly stable silicon NCs. We demonstrate by means of high resolution synchrotron XRD analysis (SPring 8) that the SiSn-NCs remain stable from room temperature up to 400,^{circ }text {C}, with a relatively small expansion of the crystal lattice. The high thermal stability observed experimentally is rationalized by means of first-principle calculations.

Ultrahigh Incorporation of Tin in SiSn Nanowires Grown via In-Plane Solid-Liquid-Solid Mechanism

We report on the growth of sn-catalyzed in-plane silicon nanowires (SiNWs) using the solid–liquid-solid (SLS) mechanism and their application to nano-electronics. The in-plane SLS growth process allows us to obtain very high tin concentrations ∼ 10 at.% (more than 1000 times the expected concentration from the phase diagram). The growth is achieved in a plasma-enhanced chemical vapor deposition reactor, in a single pump-down process. Atom probe tomography (APT) and transmission electron microscopy (TEM) are used to assess the composition of these SiSn NWs. The atomic-scale investigation shows that Sn atoms are similarly distributed in crystalline SiSn NWs grown at 300 °C and 400 °C, with different sn-enrichments along structural defects. A NW-based field-effect transistor (FET) is fabricated in which a SiSn NW is implemented as the channel for charge transport, reaching a field effect hole mobility of 80 cm2/V.s.

Metal of the "Cimmerian elite" of the North Caucasus ( on the materials of tomb 3 of the Terese burial ground)

The article publishes the results of a study of bronze items from tomb 3 of the Terese burial ground (Central North Caucasus, Karachay-Cherkessia), one of the richest burials of the Koban culture of the Central North Caucasus during the Cimmerian campaigns in Transcaucasia and Western Asia.A typological analysis of the bridle accessories of a number of imported metal items from this complex shows that the burial belongs to a war-horseman of the late 8th centuryBC, who participated in military campaigns in Transcaucasia. ED XRF analysis reveals the main alloy groups used for production of the bridle and harness attachments from the Terese tomb 3 (26 samples) and Fars burial ground (2 samples). Tin bronzes and lead-tin bronzes with low, middle, and high tin concentration and a relatively low lead content clearly dominated the Terese selection. Lost wax casting into investment clay moulds was the main manufacturing technique. The Pb-isotope data of 23 samples obtained by MC-ICP-MS reveals the different sources of copper and lead as well as the recycling of scrap metal. Polymetallic ores of the Sadonsky ore field, located in North Ossetia was considered as one of the possible ore sources. Within the framework of the studied samples, arsenic bronze was recorded only as part of the inlay of two pins, originating from the Central Georgia which were probably made to order by a highly qualified Transcaucasian jeweller.

The Formation of Magmatic-Hydrothermal Features in Sn-Mineralized and Barren Tasmanian Intrusions, Southeast Australia: Insights from Quartz Textures, Trace Elements, and Microthermometry

Abstract Tasmania is the most important tin province in Australia, having been endowed with >0.65 Mt Sn. Some granitic intrusions in western Tasmania have distinctive tourmaline- and quartz-rich magmatic-hydrothermal features, whether they are mineralized (e.g., Heemskirk Granite) or barren (Pieman Heads Granite). The Devonian Heemskirk and Pieman Heads plutons crop out on the western coast of Tasmania and are characterized by similar mineralogical and geochemical compositions and ages. The magmatic-hydrothermal textural features include tourmaline patches, tourmaline orbicules, and tourmaline-muscovite veins, as well as miarolitic cavities and quartz-fluorite-sulfide veins in the Heemskirk Granite. Cathodoluminescence (CL) imaging, laser ablation-inductively coupled plasma-mass spectrometry, and microthermometric analyses of quartz have revealed the physicochemical evolution of the magmatic-hydrothermal fluids from which these tourmaline- and quartz-bearing assemblages precipitated. High Ti quartz (20–28 ppm) in tourmaline patches, orbicules, and cavities typically have homogeneous CL-bright intensity, whereas CL-dark fractures have cut and/or offset the CL-bright and -gray domains that characterize low Ti quartz (3.4–8.5 ppm) from the tourmaline veins. The earliest fluid inclusion assemblages in the quartz-tourmaline orbicules and cavities have a salinity range from 3 to 14 wt % NaCl equiv with intermediate density and were probably trapped at lithostatic pressures of 1.57 ± 0.2 kbar and temperatures of 550° to 570°C, suggesting a depth of 5.9 ± 0.8 km. Prolonged depressurization and cooling may have led to the evolution of a brine (~39 wt % NaCl equiv salinity) from the primary magmatic liquid, which formed halite-bearing hypersaline inclusions in the tourmaline orbicules. Continuous pressure decrease explains the intense brittle failure and fluid migration outward from the apical portions of the pluton, where magmatic fluids partially mixed with and were cooled by external meteoric water. These mechanisms triggered the formation of tourmaline-muscovite-quartz veins and local cassiterite-bearing greisens from a moderate-salinity fluid (~12 wt % NaCl equiv) at temperatures of ~300°C and hydrostatic pressures of 120 bars. Retrograde dissolution textures evident from CL-bright quartz cores surrounded by oscillatory growth zones with gray CL response characterize the low Ti (<1 ppm) and high Al (500–1,000 ppm) quartz from the fluorite-sulfide veins that precipitated from a low-salinity (5.7 wt % NaCl equiv) acidic fluid at temperatures of 200° ± 25°C and hydrostatic pressures of <50 bars. High Sb concentrations (up to 80 ppm) in quartz may be an indicator of low-temperature base metal mineralization related to granitic intrusions. Abundant fluid percolation, protracted fractional crystallization, and high tin concentrations in exsolved hydrothermal fluids may explain why the Heemskirk Granite is well endowed in Sn and base metal deposits, whereas the Pieman Heads Granite is barren.

Silicon-Tin Alloyed Nanocrystals by Femtosecond Laser Plasma

Silicon’s (Si) indirect bandgap limits its absorption and possible applications, and therefore remarkable efforts are put into the possibility of fabricating a material compatible with the existing silicon technology that is also a direct bandgap material. Tin (Sn) alloying with silicon represents an exciting possibility to tune Si properties. In addition, at the quantum confinement size (<10 nm) when the material becomes a quantum dot, it becomes possible to control the electronic structure of a material by varying the size. Although the possibility to tailor the bandgap of elemental Si over a wide range has been demonstrated, it is very challenging to obtain stable alloyed SiSn quantum dots. In particular, alfa Sn has a crystal structure similar to Si with zero band gap: a diamond cubic crystal structure, and importantly affected by the crystal configuration and a possible change to a direct energy gap at sufficiently high Sn concentration. This therefore makes Sn a favorable element to create an alloy with a lower bandgap than Si. Exploiting these features would make alloyed SiSn NCs an important candidate for a broad range of applications such as next generation photovoltaic cells based on carrier multiplication, super high efficient photodetectors, fluorescent tags for biomedical applications etc. In this contribution we will discuss the synthesis paths and optoelectrical properties in the context of silicon, tin, and silicon/tin alloyed nanocrystals at high alloying concentrations. Our results show that plasma-based processes allow the synthesis of alfa tin alloyed SiSn QDs with unprecedented dimensions and alloying concentrations. We will present SiSn-QDs as the world’s highest alloys fabricated by confined plasma from femtosecond (fs) laser in liquid media with a high tin concentration of approximately 17% ever reported in literature to our knowledge. We have demonstrated for the first time the experimental and exact theoretical calculation determination of the thermal stability of the SiSn-NCs at those concentrations. We study their electronic properties by means of an approximate band structure suitable for finite-sized systems (quasi-band structure) derived from first-principles calculations. This work therefore advances the current state of the art, provides opportunities to compare and verify theoretical results and offer important directions for applications.

Silicon-Tin Alloyed Nanocrystals by Femtosecond Laser Plasma

Here we discuss the synthesis paths and optoelectronic properties in the context of alpha tin (α-Sn) phase and silicon/tin (SiSn) alloyed nanocrystals (NCs). We discuss the possibilities and benefits of stabilizing α-Sn in larger sized nanocrystals by alloying with silicon. We demonstrate that plasma-based processes allow the synthesis of stable elemental α-Sn NCs and also alloyed α-Sn based SiSn NCs with quantum confinement size and extraordinarily high Sn concentrations: i.e. SiSn NCs fabricated by confined plasma from femtosecond (fs) laser in liquid media with a high tin concentration of approximately 17%. We also discuss the experimental and exact theoretical calculation determination of the thermal stability of the α-Sn based nanocrystals.

LA-ICPMS U-Pb dating reveals cassiterite inheritance in the Yazov granite, Eastern Siberia: Implications for tin mineralization

U-Pb dating of cassiterite and zircon from the Yazov granite (Transbaikalia region, Eastern Siberia, Russia) and cassiterite from spatially associated tin mineralization in the Tuyukan ore district in the Tonod uplift was conducted using in situ laser ablation inductively coupled plasma mass spectrometry. These analyses allow comparison of isotopic systematics for both minerals, especially related to transport in granitic magma. These data are also useful for understanding possible genetic links between the granite and the tin mineralization. Most of the U-Pb zircon analyses define a 206Pb/238U age of 719 ± 15 Ma for the granite; in addition, several zircon cores define an inheritance age of 1839 ± 21 Ma. U-Pb data for 10 nearly concordant analyses of disseminated cassiterite from the same samples yield a 206Pb/238U age of 1838 ± 34 Ma. This is the first documented evidence of cassiterite inheritance in granitic magma. These data indicate the robust character of U-Pb isotope systematics in cassiterite, comparable to that in zircon. The presence of numerous inclusions of cassiterite in zircon from the Yazov granite (revealed by nanotomography) supports the interpretation of inherited cassiterite included during Neoproterozoic zircon crystallization. The data indicate that high tin concentrations in the Yazov granite are due to the incorporation of older cassiterite crystals from country rock, not coeval cassiterite crystallization. Cassiterite samples from two ore occurrences spatially associated with the Yazov granite yield Pb-Pb isochron ages of 1.86–1.82 Ga, indicating that tin mineralization occurred in the Paleoproterozoic, nearly 1 Ga before emplacement of the Yazov granite. Tin mineralization of the ore region is probably related to ~ 1.85 Ga Chuya-Kodar tin-bearing granitic rocks that host tin deposits. These results have broad implications for understanding how critical elements, such as tin, may become enriched in rare-metal granites and how they are related to regional to global geodynamic processes.

Planning the Dewatering of a Tailings Storage Facility

The San Rafael mine in southern Peru produces over 10% of the world’s tin. The decision was made to reprocess some of its oldest tailings, due to their volume and high tin concentrations. This tailing storage facility was partially saturated and required a dewatering process to allow mining. This paper describes the conducted activities for this dewatering, including basic engineering studies focused on hydrogeological characterization of the tailings, recommended tests and modelling to define a detailed engineering design, and developing an appropriate construction strategy. In addition, there were tasks associated with operating the dewatering system, infrastructure maintenance, and a real-time follow-up implementation program to monitor the desaturation. The system’s historical evolution, a year of dewatering, and the beginning of mining activities are reviewed.

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.

Growth of Tensile Strained Poly Germanium Thin Film on Glass Substrates by High Speed Continuous Wave Laser Annealing, and its Application to Germanium-Tin

To realize next generation electronics, liquid phase crystallization of germanium based materials on quartz substrates is investigated by continuous wave laser annealing system which enables microsecond annealing. As a result, large grain polycrystalline germanium thin film with ∼0.6% tensile strain has successfully grown on quartz substrates. Moreover, we have applied this method on germanium-tin thin film growth and realized germanium-tin crystals with high substitutional tin concentration (up to ∼13%). By using these films, modulation phenomena of tin concentration in the crystals depending on annealing time were observed. From the phenomena, we could also closely discuss about strong correlation of substitutional Sn concentration on Raman signals. These findings and discussions will facilitate the study of germanium-tin thin film growth and characterization.

Cross‐Section Analysis of the Composition of Sprayed Cu2ZnSnS4 Thin Films by XPS, EDS, and Multi‐Wavelength Raman Spectroscopy

A detailed cross‐section analysis of the chemical composition of sprayed Cu2ZnSnS4 thin films is presented. X‐ray diffraction (XRD), energy dispersive spectroscopy (EDS), X‐ray photoelectron spectroscopy (XPS), and Raman spectroscopy (with near‐IR, visible, and UV‐lasers) are used to demonstrate that while CZTS effectively forms within the bulk of the film, there is some degree of element segregation, formation of undesirable secondary phases, and the presence of a disordered kesterite structure across the film. Different penetration depths of the excitation signals correspond to the many different surface sensitive techniques employed in this work. XPS results reveal that the surface of Cu4ZnSnS4 (CZTS) films presents a high concentration of tin and zinc and a low sulfur concentration, while being highly depleted in copper. EDS, XRD, and infrared Raman spectroscopy confirm that the composition of as‐sprayed and sulfurized films is close to stoichiometric Cu2ZnSnS4. Resonant UV‐Raman spectroscopy helps to identify secondary phases located at the external surface of sprayed and sulfurized CZTS films (mainly ZnS, ZnO), while VIS‐Raman spectroscopy helps to identify a disordered kesterite structure close to the surface. Secondary phases need to be chemically etched when aiming at incorporating kesterite films obtained by spray pyrolysis into photovoltaic devices.

Environmental Effects of the Technology Transition from Liquid–Crystal Display (LCD) to Organic Light-Emitting Diode (OLED) Display from an E-Waste Management Perspective

Organic light-emitting diode (OLED) displays are applied to various electronic devices such as smartphones and televisions in our society, replacing liquid–crystal display (LCD) due to many advantages: self-emitting property, high contrast, slimness, and flexibility. Although OLED consists mostly of organic substances, because it was developed to reduce the consumptions of rare and precious metals, OLED display has a possibility to contain more metal-based components than LCD; for instance, a pixel circuit for OLED needs two thin-film transistors (TFTs), whereas that for LCD does one. Thus, this study was intended to assess and compare possible environmental impacts due to metals in an OLED display and an LCD on a same screen size basis, to examine environmental effects of the technology transition. Hazardous waste potentials at end-of-life were examined based on metal leachability tests, and resource depletion and toxicity potentials were evaluated based on life cycle impact assessment methods. The leachability test results showed that the OLED display has higher hazardous potential than an LCD due to excessive levels of leachability for many metals under California state regulation. The OLED display had 1000–2300 times higher resource depletion potentials than the LCD due primarily to the high concentrations of gold, selenium, silver, palladium, and tin. The OLED display also had 2–600 times higher toxicity potentials due primarily to the high concentrations of arsenic, cadmium, chromium, and antimony. This study can be used to motivate waste recyclers and managers to actively collect waste OLED displays for circular economy and to direct manufactures to develop more environmental-friendly OLED displays for sustainable society. This study evaluates and compares hazardous, resource depletion, and toxic potentials from metals in a Liquid–Crystal Display (LCD) and an Organic Light-Emitting Diode (OLED) Display to examine the effect of the technology transition on environmental impacts.

Phytotoxicity of tin mine waste and accumulation of involved heavy metals in common buckwheat (Fagopyrum esculentum Moench)

ABSTRACTExtraction and processing of cassiterite (SnO2) left large tailings with high concentrations of tin, tungsten, molybdenum and lithium. Information on the phytotoxicity of mine waste is important with regard to ecological hazards. Exposure studies help to identify plants useful for the stabilization of waste tips and the phytomining of metals. A greenhouse study was performed using a dilution series of mine waste and four crops, a halophytic and a metallophytic species to derive dose response curves. Based on effective doses for growth reductions, sensitivity increased in the following order: maize > common buckwheat > quinoa > garden bean. Element analyses in different species and compartments of common buckwheat grown in a mixture of standard soil and 25% of the mine waste showed that only low levels of the metals were taken up and that transfer to seed tissues was negligible. As indicated by soil metal levels prior to and after the experiment, only lithium and arsenic proved to be plant available and reached high levels in green tissues while seed levels were low. The experiment confirmed differences in the uptake of metals with regard to elements and species. Common buckwheat is a suited candidate for cultivation on metal polluted soils.

Aqueous phase hydrogenation of furfural using carbon-supported Ru and RuSn catalysts

The aqueous phase hydrogenation (APH) of furfural was studied over carbon-supported monometallic Ru and bimetallic RuSn catalysts at 90°C and 1.25MPa. Tin was added via Surface Organometallic Chemistry on Metals techniques and its effect was a function of the Sn/Ru atomic ratio. Thus, the addition of Sn in a Sn/Ru ratio of 0.4 promoted the CO hydrogenation reaching a selectivity towards furfuryl alcohol over 85% throughout the course of the reaction. A higher concentration of tin does not improve the situation. It seems to be a compromise between the dilution of Ru sites, active for the hydrogenation reaction, and the promoting effect of Sn. TEM, TPR and XPS characterization indicate the strong interaction between Ru and Sn in all the bimetallic catalysts. Finally, the reuse of the catalyst was analyzed.

Optical Properties of Eu3+-Doped Aluminophosphate Glass with a High Concentration of Silver and Tin

The optical properties of Eu3+-doped aluminophosphate glass containing a high concentration of Ag2O and SnO co-dopants (8 mol% of each) are reported. Glass preparation is carried out by melt-quenching, and a subsequent in situ monitored heat treatment (HT) is carried out for the reduction of ionic silver to Ag nanoparticles (NPs) via reducing agent tin(II). An enhanced ultraviolet broadband excitation range for Eu3+ ions is realized for the melt-quenched glass, likely due to the creation of molecule-like silver species such as Ag+–Ag+ dimers. The real-time optical monitoring of the glass during isothermal HT shows the steady development of the surface plasmon resonance peak of Ag NPs near 420 nm. Concurrently exciting Eu3+ ions in situ at 420 nm unveils the plasmonic diluent effect manifested through the quenching of Eu3+ luminescence. The decay times of the 5D0 emitting state in Eu3+ ions in the melt-quenched and NP-doped glasses are measured and discussed.

Surface analysis of epitaxially grown GeSn alloys with Sn contents between 15% and 18%

Metastable Germanium–tin (GeSn) layers with rather high Sn content between 15% and 18% grown on Si substrates by molecular beam epitaxy were analyzed for the morphological changes on a surface before and after reaching critical layer parameters (thickness, Sn content, and growth temperature) for surface roughening. Atomic-force microscopy investigations were performed as a function of thickness and separately for varying Sn concentrations in the GeSn layer. Epitaxial growth of metastable, uniform GeSn (15% Sn content) layers is obtained up to a critical thickness which increases from about 80 to above 200 nm by reducing the nominal growth temperature from 160 to 140 °C. Phase separation of the complete layer into tin-rich surface protrusions and a Ge-rich matrix takes place beyond the critical thickness. This surface roughening via phase separation was not observed in earlier investigations with lower Sn concentrations (<6%). Tin depletion in the GeSn matrix was confirmed by using energy-dispersive X-ray spectroscopy measurements showing residual Sn concentration below 5%. Additionally, creation of droplets with high concentration of tin on the surfaces was confirmed by energy-dispersive X-ray spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd.

Strategies to Reduce Tin and Other Metals in Electronic Cigarette Aerosol.

BackgroundMetals are present in electronic cigarette (EC) fluid and aerosol and may present health risks to users.ObjectiveThe objective of this study was to measure the amounts of tin, copper, zinc, silver, nickel and chromium in the aerosol from four brands of EC and to identify the sources of these metals by examining the elemental composition of the atomizer components.MethodsFour brands of popular EC were dissected and the cartomizers were examined microscopically. Elemental composition of cartomizer components was determined using integrated energy dispersive X-ray microanalysis, and the concentrations of the tin, copper, zinc silver, nickel, and chromium in the aerosol were determined for each brand using inductively coupled plasma optical emission spectroscopy.ResultsAll filaments were made of nickel and chromium. Thick wires were copper coated with either tin or silver. Wires were joined to each other by tin solder, brazing, or by brass clamps. High concentrations of tin were detected in the aerosol when tin solder joints were friable. Tin coating on copper wires also contributed to tin in the aerosol.ConclusionsTin concentrations in EC aerosols varied both within and between brands. Tin in aerosol was reduced by coating the thick wire with silver rather than tin, placing stable tin solder joints outside the atomizing chamber, joining wires with brass clamps or by brazing rather than soldering wires. These data demonstrate the feasibility of removing tin and other unwanted metals from EC aerosol by altering designs and using materials of suitable quality.

SnxGe1–x Alloy Nanocrystals: A First Step toward Solution-Processed Group IV Photovoltaics

Nontoxic, sustainable, and cost-effective, Group IV materials are attractive for a broad range of electronic and optoelectronic applications, although the indirect principal band gaps of silicon and germanium (Ge) present complications that impact device design and cost. Previous studies have shown that the band structures of these materials can be modified by the influence of quantum confinement in nanostructures or by alloying with tin (Sn) in metastable thin films; to date, neither method has produced a material with a direct band gap of appropriate energy for application in, for example, efficient solar photovoltaics. We have developed a facile colloidal method for the synthesis of size-controlled, homogeneous SnxGe1–x alloy nanocrystals (NCs) with remarkably high tin concentration (x up to 0.42). We demonstrate that NCs of the same size exhibit a pronounced, systematic red-shift in the optical band gap, and a significant increase in molar absorptivity, with increasing Sn-content, and a measurable pho...