Sn Thin Films Research Articles

Characterization of superconducting Sn thin films and their application to ferromagnet-superconductor hybrids

We characterize thermally quench condensed (~80 K) Sn thin films of two different thicknesses to explore their usefulness for vortex studies. The coherence length and the London penetration depth near the critical temperature indicate that the thin films are in the dirty limit and behave as type II superconductors. Furthermore, when we add ferromagnetic nanostripes on top of the Sn thin films, the ferromagnet-superconductor hybrids show hysteric and anisotropic behavior. A ferromagnet-superconductor hybrid with a thinner Sn film exhibits a stronger effect.

Structural and optical properties of CdS:Sn thin films prepared by chemical spray pyrolysis method

CdS and CdS:Sn thin films were successfully deposited on glasssubstrates by spray pyrolysis method. The films were grown atsubstrate temperatures 300 C°. The effects of Sn concentration on thestructural and optical properties were studied.The XRD profiles showed that the films are polycrystalline withhexagonal structure grown preferentially along the (002) axis. Theoptical studies exhibit direct allowed transition. Energy band gapvary from 3.2 to 2.7 eV.

Dynamics of the ions emitted in backward and forward direction during laser ablation of thin Sn film

Laser-generated ions emitted in backward and forward directions from an 80 nm thick Sn film deposited on the soda lime glass were investigated in the range of laser fluence (93–521 J/cm2). The ion collectors operating in time-of-flight configuration were employed to measure charge density and energy of the Sn ions emitted in both directions. As expected, the charge density and peak energy of the ions emitted in backward direction were found to increase with the laser fluence: the ion charge density and peak ion energy increased by a factor of three and ten, respectively. In contrast, the charge density of the ions emitted in forward direction decreased and their energy did not seem to vary with laser fluence. The surface morphology of the beam spot at the film and substrate was examined with the help of an optical microscope. The heat conduction equation is numerically solved to simulate the temporal distribution of temperature at the surface and along depth of the Sn film. A model, based on the results of optical microscopy and computer simulation, is proposed to explain the peculiar behaviour of the charge density and energy of the ions emitted in forward direction.

Insight on the Failure Mechanism of Sn Electrodes for Sodium-Ion Batteries: Evidence of Pore Formation during Sodiation and Crack Formation during Desodiation

The development of Sn based anode materials for sodium ion batteries is mainly hindered by the limited understanding of sodiation/desodiation mechanisms inside the active material, which typically results in electrode damage. Herein, we report a post-mortem ex-situ scanning electron microscopic analysis of Sn thin film motivated by the intention to elucidate these structural mechanisms. Our results reveal for the first time that the surface of Sn electrode film becomes highly porous during sodiation with no presence of obvious cracks, a surprising result when compared to previous reports performed on Sn particles. Even more surprisingly, sequential ex-situ SEM observations demonstrate that, once the desodiation starts and reaches the second desodiation plateau (0.28 V), obvious cracks in the Sn film are instead observed along with porous islands of active material. These islands appear as aggregated particles which further split into smaller islands when the desodiation potential reaches its maximum value...

Enhanced magneto-caloric effect upon fourth element (Cu, Fe, Co) substitution in Ni–Mn–Sn thin films

The effect of small amounts of fourth element X (Cu, Fe, Co) substitution on magnetic transition and magneto-caloric properties of Ni–Mn–Sn thin films has been investigated. The ternary and quaternary films show cubic L21 structure with room-temperature ferromagnetism after heat treatment. The Curie temperature of the film is close to room temperature which does not shift much upon X (Cu, Fe, Co) substitution. The variations in magnetic entropy change (ΔSM) and refrigeration capacity (RC) with Cu/Co substitution are very less. However, an enhancement in ΔSM and RC from − 3.85 × 104 erg/cc K (− 0.47 J/kg K) and 1.50 × 106 erg/cc (18.3 J/kg) to − 5.66 × 104 erg/cc K (− 0.69 J/kg K) and 2.50 × 106 erg/cc (30.4 J/kg) is observed with 3.6 at.% Fe substitution for a field change of 18 kOe. This shows that Fe is the ideal fourth element for enhancing magneto-caloric effect in Ni–Mn–Sn thin films.

Tuning the excitonic properties of ZnO:Sn thin films

The effects of Sn doping, deposition temperature, and post-annealing treatment on the excitonic behavior of ZnO:Sn (SZO) thin films deposited by dc-unbalanced magnetron sputtering have been studied. Sn doping induces the decrease of grain size and promotes the formation of oxygen vacancy-related trap states as indicated by A1 LO mode in Raman spectra and green emission in photoluminescence spectra. Using a critical point analysis of the dielectric functions from spectroscopic ellipsometry data analysis, Sn doping blueshifts the excitonic absorption and decreases the exciton lifetime via screening the electron-hole Coulomb interaction. By varying the deposition temperature from room temperature up to 300 °C (SZO-3), there is no change in excitonic absorption. Then, annealing of SZO-3 at 600 °C under oxygen environment (SZO-6) strongly improves the excitonic absorption as well as its lifetime. Critical point analysis on SZO-6 sample clearly reveals the excitonic transition at 3.38 eV and exciton-phonon complexes at 3.66 eV. Thus, the result is important to improve the functionality of doped ZnO with strong excitonic absorption for optoelectronic applications.

Studying the morphology, structure and band diagram of thin GeSiSn films and their mid-infrared photoresponse

The initial stages of Ge1−x−ySixSny film growth on Ge substrate were investigated and the kinetic diagram of the morphological state for GeSiSn films was built. The kinetic diagram for the GeSiSn films on the Ge substrate was compared to the kinetic diagram for GeSiSn films on Si substrate. New phase diagrams of the superstructural changes on the Sn surface were obtained at different initial conditions of the Sn cover deposition. The Sn film growth was performed at room temperature and 200 °C. Superstructures such as (7 × 1), (8 × 1) and (10 × 1) were first obtained on the Sn surface. The phase diagrams allow for determining and controlling the surface Sn cover during the multilayer periodical structures growth, as well as demonstrating the separate interest in obtaining the epitaxial thin Sn films. The multilayer structure growth with the pseudomorphic GeSiSn films on Ge and Si substrates was investigated using the phase diagrams for the superstructural changes of the Sn film and reflection high energy electron diffraction (RHEED) pattern. The rocking curves obtained by x-ray diffraction from the multilayer structures containing the GeSiSn layers with the Sn content up to 14% on the Ge and Si substrates demonstrate the pseudomorphic GeSiSn film state, sharp interfaces, as well as the conservation of the periodicity and content in all periods. The comparison of band diagrams based on Ge1−x−ySixSny/Si and Ge1−x−ySixSny/Ge heterostructures was performed, and the conditions, which correspond to the transition to the direct bandgap Ge1−x−ySixSny material, were determined. Based on the multilayer structures with the Ge1−x−ySixSny/Si heterojunction, p-i-n diodes were created and a vertical photocurrent was measured in the photovoltaic regime at zero bias. The p-i-n diode photocurrent extends at least to 4 μm.

Optical characterisation of amorphous Se–Te–Sn thin films

Optical characterization of Sn doped Se–Te thin films has been carried out. The characterization has been carried out using transmission spectra in range 500–2500 nm. Bulk samples were prepared using melt quenching technique and thin films were deposited using thermal evaporation. XRD analysis was used to confirm the amorphous nature of prepared samples. Optical constants such as refractive index and extinction coefficient have been determined using Swanepoel’s method. Variation of refractive index with wavelength has been analysed using single effective oscillator model. Optical band gap of the deposited films was calculated using Tauc plots. The observed properties have been explained using the chemical bond approach.

High‐Pressure Evaporation‐Based Nanoporous Black Sn for Enhanced Performance of Lithium‐Ion Battery Anodes

AbstractIncreasing the surface area to improve chemical activity is an unending task from conventional catalysis to recently emerging electrochemical energy conversion and storage. Here, a simple, vacuum‐deposition‐based method to form nanoporous structures of metals is reported. By utilizing thermal evaporation at a high pressure, fractal‐like nanoporous structures of Sn with porosity exceeding 98% are synthesized. The obtained nanostructure consists of nanoparticle aggregates, and the morphology can be controlled by adjusting the working pressure. The formation of the nanoporous structure is explained by homogeneous nucleation and diffusion‐limited aggregation, where nanoparticles produced by the repeated collisions of evaporated atoms adhere to the substrate without diffusion, forming porous aggregates. Due to the easy oxidation of Sn, the constituent nanoparticles are covered with amorphous SnOx and crystalline SnO phases. When the nanoporous Sn/SnOx aggregates are applied to a lithium‐ion battery anode through direct deposition on a Cu foil current collector without binders or conducting additives, the nanoporous Sn/SnOx anode shows greatly enhanced cyclability and exceptional rate performance compared to those of a dense Sn thin film anode. The approach investigated in this work is expected to provide a new platform to other fields that require highly porous structures.

Silver-doped tin oxide for electrical property enhancement in p-type channel thin film transistor

Though tin oxide (SnO) is one of the strong candidates for p-type oxide semiconductor thin film transistors (TFTs), poor properties and a narrow window of deposition condition are obstacles for implementation. An Ag-doped Sn thin film was studied for the improvement of electrical performance of TFTs. SnO and Ag-doped SnO thin films were deposited by direct current magnetron sputtering as the channel for thin film transistors. The concentration of Ag doping was controlled by the amount of Ag pellets in the sputtering target preparation. A change in oxide states was observed in an Ag-doped SnO film, which can lead to the reduction of the Sn4+ oxide phase. Ag-doped SnO showed improvement of carrier mobility and concentration and resulted in improved electrical characteristics.

Structure and Electrical Properties of Zirconium-Doped Tin-Oxide Films

Thin Zr-stabilized SnO2 films are fabricated by ion-beam reactive sputtering. The amorphous thin-film SnO2 samples with various Zr concentrations are synthesized in a single production process. The influence of heat treatment on the structure and electrical properties of the synthesized films is studied. The onset of crystallization in thin-film Sn–Zr–O systems is observed at 673 and 773 K, which is accompanied by the appearance of metastable phases. Being heated to 873 K, these phases are transformed into Sn + Sn2O3. It is found that the electrotransfer the film crystallization at temperatures close to room temperature is thermally activated with an activation energy of ~0.78 eV. Tin-oxide films doped with Zr from 0.6 to 3.9 at % manifest the property of hydrogen-gas sensitivity after crystallization.

Microstructure and crystallization kinetics of Ge2Sb2Te5–Sn phase change materials

In this paper, the effects of Sn doping on the microstructure and electrical properties of amorphous and crystalline Ge2Sb2Te5 thin films are reported. The thin films bonding states are measured through X-ray photoelectron spectroscopy (XPS) and micro-Raman spectroscopy, which prove that the bonding states of Ge2Sb2Te5–Sn thin films regularly change with the additions of various Sn contents. Sn atoms alter the chemical surrounding of Te atoms significantly, having a low impact on the bonding environment of Sb atoms, since the additional Sn atoms bond with Te atoms and lead to the SnTe phase formation. Both the homogeneity of bonding characteristics and crystallinity in Ge2Sb2Te5–Sn thin films are improved. The atomic arrangement of the crystalline states Ge2Sb2Te5–Sn thin films is also obtained. It could be inferred that the Sn addition lead to higher crystalline interplanar spacing and arrangement of many disordered atoms. Furthermore, the corresponding activation energy value (EA) of Ge2Sb2Te5–Sn thin films is calculated. This display that the EA values of Ge2Sb2Te5–Sn increase compared to the pure Ge2Sb2Te5 thin films, since the Ge2Sb2Te5–Sn thin film structures are stabilized due to the compressed bonds and various bonding states.

Transformation Plasticity Provides Insights into Concurrent Phase Transformation and Stress Relaxation Observed during Electrochemical Li Alloying of Sn Thin Film

Stress development during electrochemical alloying/insertion of “guest species” into electrode materials is known to considerably affect the performance and integrity of the concerned electrode. Mo...

Combined effects of surface oxidation and interfacial intermetallic compound growth on solderability degradation of electrodeposited tin thin films on copper substrate due to isothermal ageing

We report new insights into the solder wettability degradation of Sn thin films on Cu under 155 °C isothermal ageing. A multiscale wettability degradation model was established, reflecting quantitatively the surface oxidation and interfacial intermetallic compound (IMC) growth, on the basis of solder wetting behaviour. The thermal oxidation of Sn exhibited heterogeneous inward thickening, lateral expanding and outward platelet-like growth, forming nanocrystalline, oxygen-deficient SnO2 with pronounced voiding/cracking propensity. Unlike a commonly held belief that the initial wettability loss is due to surface-exposing and oxidation of IMCs, it was found from dual combined effects of inward surface oxidation and outward IMC growth.

Band gap tailoring of chemically synthesized lead sulfide thin films by in situ Sn doping

In the present report, undoped and tin (Sn)‐doped lead sulfide thin films were synthesized via chemical bath deposition method. The effects of Sn molar concentration on the optical, structural, and morphological properties were systematically studied. The concentration of Sn in the chemical bath was characterized by the ratio of [Sn+2]/[Pb+2] and varied from 0 to 15 at.%. Both doped and undoped thin films were polycrystalline in nature with a face‐centered cubic crystal structure; however, the preferred orientations of the crystallites were varied along the (111) and (200) planes with Sn‐doping concentration. The X‐ray powder diffraction results also showed that peak intensities and the crystalline size were decreased with increasing Sn concentration. The lattice constant varied with Sn concentration and found in the range of 6.020 to 5.944 Å. The variation of Sn concentration in PbS:Sn thin films were confirmed by energy dispersive X‐ray analyses study. The scanning electron microscope and atomic force microscopy studies revealed that Sn doping had a critical role on the surface roughness and morphology of the PbS:Sn thin films. The optical band gap study showed that the band gap of PbS:Sn thin films were engineered from 0.676 to 1.345 eV because of incorporation of Sn+2 ions via cost‐effective chemical route. Room temperature photoluminescence spectra showed a well‐defined peak at 427 nm and shoulders at 405 and 462 nm for all Sn‐doped and undoped PbS samples.

Preparation of carbon cloth supported Sn thin film for structural lithium-ion battery anodes

Commercial carbon fibers have been studied in structural lithium-ion batteries (SLIBs) with good promises. However, the currently urgent issue is the limitation in capacity in today's SLIBs. In this work, we focus on fabrication of integrated Sn/carbon cloth (Sn/CC) composite with Sn nanoparticles uniformly coated onto the surface of the CCs with close connection between them. Due to the combined superiority of the Sn with high theoretical specific capacity and the carbon cloth with good conductivity and buffer effect, the prepared Sn/CC composite are expected to be employed as an anode material for future SLIBs. As a result, even though in high mass loading up to 5.19 mg cm−2, a high reversible capacity of 2.23 mAh cm−2 (i.e. 431.5 mAh g−1) is maintained over 100 cycles at a current density of 100 mA cm−2, showing a huge increase almost 3.3 times as high as the reported carbon fibers in SLIBs. Furthermore, even at a high current density of 2000 mA cm−2, the discharge capacity can still reach to 1.18 mAh cm−2. These good electrochemical performances in capacity could urgently solve the current issue that the limitation of capacity in current SLIBs when using commercial carbon fibers as anode materials.

Doping And Annealing Effect On Evaporation Of ZnO Thin Films

The present study carried out to show the structure and optical properties of doped ZnO:Sn thin films that have been deposition on a glass substrate by thermal evaporation (using Zn metal). The percentage of dopant is (3, 5, 7, & 9)%. The annealing temperature was 200 oC fixed for one hour annealing time. The result of XRD shows the presence of (100), (002) and (101) are the diffraction peaks of all thin films. The crystalline size was found to be increased with Sn doping. The FWHM values of the peaks were found to increase with doping. The direct optical band gap was calculated and found to be (3.24, 3.21, 3.2, 2.72, 2.88) e.V for pure and doped thin films respectively.

Electrophoretic deposition of Sn-doped TiO2 nanoparticles and its optical and photocatalytic properties

In this research, Sn-doped TiO2 (Sn–TiO2) nanoparticles were synthesized by a simple sol–gel method. The structure and composition of the as-prepared sample were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and ultraviolet–visible absorption spectroscopy. Electrophoretic deposition (EPD) technique was used to deposit thin films of Sn–TiO2 on 316L stainless steel (316L SS) substrate. In order to achieve a fine and high-quality layer on the electrode surface, N-phenyl-p-phenylenediamine (NPPDA) was used as a new dispersant and charging agent in ethanolic suspensions. Based on zeta potential and conductivity measurements of the suspensions, an optimum concentration of the NPPDA dispersant was found to be 3.0 g l−1. The in-situ EPD kinetics was also studied. The prepared Sn–TiO2 film was used for the photodegradation of methylene blue (MB) under UV, visible and sun lights. The results revealed that the Sn–TiO2 film could be able to degrade the MB under sunlight. The calculated degradations were 44, 65, and 73% after 2, 4 and 5 h, respectively. The relation between \(\ln \left( {\frac{{{{\text{A}}_0}}}{{\text{A}}}} \right)\) and time was linear, so it was proved that the photocatalytic degradation of MB can be characterized by pseudo-first order reaction kinetics.

Metallic Adhesive Layers for Ag‐Based First Surface Mirrors

Metallic thin films have been evaluated as adhesive layers for first surface mirrors. Thin films (0.5–4 nm thick) of Cr, Cu, Ge, Sn, and Ni, capped with an over layer of 100 nm of Ag have been deposited by means of ion assisted electron beam evaporation onto glass substrates. The specular reflectance, conductivity, morphology, adhesion, and abrasion resistance of the mirrors have been assessed and compared. This work demonstrates the superior Ni and Ge adhesion and abrasion resistance to Ag thin films, while Cr and again Ni are the best candidates in terms of reflectance enhancement. In particular, 4 nm of Ni increases the Ag reflectance from 95.7% to 96.7%, exhibits the strongest adhesion as determined by the cross hatch tape test and the lowest loss of material after the different abrasion tests is just 50% in comparison to 100% for Ag‐coated glass substrates.

Preparation of tin oxide (SnO2) thin films using thermal oxidation

The present research study deals with the preparation of tin oxide (SnO2) nanostructures using thermal oxidation method. At first, Sn thin film was deposited on silicon (Si) substrate by thermal evaporation and then, thermal oxidation of the deposited Sn thin film was carried out at the growth temperature of 100°C with growth time of 1 hour in tube furnace. The structural property of SnO2 nanostructures was investigated by using FESEM and EDX. The FESEM results showed that Sn was successfully grown on Si substrate and the SnO2 nanoparticles with diameters of 97.5nm to 142nm were recorded. It was observed that the particles were agglomerated to form the SnO2 particles. The radiation of sunlight illumination was conducted for four consecutive sunny days and the results showed that the highest reading 189.9 W/m2 was recorded at day two for the daytime temperature 38°C. It was also noticed that the highest solar radiation percentage at day two was measured 18.9%.