Deposited Tin Oxide Research Articles

Anti-icing nano SnO2 coated metallic surface wettability: optimization via statistical design

Super-hydrophobic tin oxide surfaces were fabricated and the anti-icing potential was investigated. The main purpose of the study was the examination of the seed-layer effect on the wettability of the prepared surfaces. The seeding was performed on Al-substrates by dip coating and consequently the common chemical bath deposition method was used for tin oxide deposition. Seed-layers were deposited under different conditions including combinations of some factors such as surfactant type and concentration, deposition cycles, the metallic precursor concentrations. Taguchi L18 design was used for deposited surfaces' wettability optimization, and Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and atomic force microscopy (AFM) analyses were used for characterization of seed-layers and coated surfaces. Formation of nanostructured seed-layers was illustrated by FE-SEM images. Moreover, a hydrophobic tin oxide surface having the water contact angle (WCA) of 137° was fabricated without any post-treatment step. Finally, the surface chemical modification was carried out by palmitic, lauric, and stearic acids. Accordingly, a superhydrophobic surface (WCA = 157.5° and contact angle hysteresis (CAH) = 2.5°) was achieved as the optimized sample. The anti-icing characteristic of the modified surface was examined and the results proved the success of the process.

Plasma treatment to tailor growth and photoelectric performance of plasma-enhanced atomic layer deposition SnOx infrared transparent conductive thin films

The performance of atomic layer deposition films is mainly limited by precursor residues, low crystallinity and densities due to low deposition temperatures. Here, we used atomic layer deposition to deposit tin oxide thin films at a relatively low temperature of 250 °C. At this temperature, the change in the valence of Sn due to precursor residue is eliminated by layer-by-layer Ar plasma treatment, and the crystallinity of the films is improved. The effects of Ar plasma treatment power and Ar treatment time on the structural and optoelectronic properties were investigated. It was found that Ar plasma treatment time more significantly affects the surface morphology and the optical and electrical properties of the film. The film is transparent to both visible and near-infrared light over a wide range of wavelengths from 400 nm to at least 5000 nm. The film resistivity can be as low as 1.117 × 10−3 Ω·cm. The film has a relatively low level of residual stress due to the fact that there is no need to improve the crystallinity of the film by conventional high temperature annealing. On the basis of the high transparency and high conductivity of the SnOx films with layer by layer Ar plasma treatment in situ, the films can be applied as electromagnetic shielding windows for photodetectors.

Direct successive ionic layer deposition of nanoscale iridium and tin oxide on titanium surface for electrocatalytic application in oxygen evolution reaction during water electrolysis in acidic medium

Abstract In this paper, we propose a novel promising route for the direct synthesis of nanoscale iridium and tin oxide nanolayers by a successive ionic layer deposition method (SILD). The precursors for the synthesis included an aqueous solution of SnF2 with an equilibrium pH value and the colloidal solution of IrOx∙nH2O nanoparticles and Na2[Ir(OH)6] mixture with pH = 10.5, obtained by the alkaline hydrolysis of the H2IrCl6 solution. The synthesized nanoscale oxide exhibited electrocatalytic properties in the oxygen evolution reaction (OER) upon water splitting in the acidic medium. A series of samples were obtained, synthesized as a result of 10, 30, and 50 SILD processing cycles. It was found that the films obtained as a result of 30 SILD cycles and heated in argon at a temperature of 300 °C had the best electrocatalytic properties in the reaction of oxygen evolution in the HClO4 solution. For these films, the overpotential value at a current density of 10 mA/cm2 was 288 mV and the Tafel coefficient value totaled 56 mV/dec. Investigations by SEM, TEM, EDX, XRD, XPS and FTIR spectroscopy revealed that the samples were built of Ir0.7SnOx∙nH2O amorphous nanoparticles with a size of 10–20 nm. For this kind of electrode, estimation of the specific mass of iridium showed that its amount is about 0.02 mg/cm2. It is suggested that the new synthetic method may serve as the basis for creating a wide range of coatings for electrodes in electrochemical devices, including electrochemical sensors, electrical stimulators, electrochromic devices, etc.

A NEW APPROACH TO THE USE OF TIN OXIDE FILMS FOR RENEWABLE ENERGY SOURCES

In this paper, the technologies of obtaining active elements for lithium-ion batteries based on sputtering of a film of graphite and applying a layer of tin oxide on it are considered. The result obtained, when using a SnO2 film, shows that the parameters of the irreversible capacitance can exceed the values of the return capacitance obtained simply on puregraphite (300-350 mAh / g). This shows the prospect of creating an active anode with a tin graphite oxide structure. Thedirections of optimization of technological processes of obtaining films, the importance of correct selection of thicknessratios, as well as the possibility of transition to the deposition of tin oxide on the carbon structure are highlighted in thework.In contrast to conventional technology, we have been producing anode system of electrode lithium-ion battery using vacuum sputtering on copper foil, which method of high-frequency magnetron deposition applied a layer of graphite and tin, meeting a number of technological requirements.The graphite tin oxide obtained by us has an extremely large variation of values from 380 mAh / g to 690 mAh / g. This is probably due to the raw technology of producing tin graphite by oxidation, as a result of multiphase inclusions of tin oxide. The ambiguity of the graphite structure depending on the film thickness also affects the result.From the presented results, it follows that intensive search for alternative carbon materials for the anode of lithium-ion battery is underway. Although none of the studied materials can compete with carbon at present, it is hoped that composites and nanocomposites of carbon and non-carbon materials will find application in the production of LIA in thenear future.On the basis of the obtained results the possibility of improvement of technical solutions and introduction of new technological processes in the production of lithium-ion batteries is shown, as well as possible directions of improvement of their operational characteristics are analyzed.

Tin oxysulfide composite thin films based on atomic layer deposition of tin sulfide and tin oxide using Sn(dmamp)2 as Sn precursor

Sn(II) dimethylamino-2-methyl-2-propoxy (Sn(dmamp)2) with water and hydrogen sulfide as oxygen and sulfur sources was employed in atomic layer deposition (ALD) of composite tin oxysulfide thin films abbreviated by Sn(O,S) made up of tin oxide (SnO) and tin sulfide (SnS) thin films employed as end members in addition to tin oxide and tin sulfide. Both SnO and SnS thin films demonstrate temperature-independent growth rates per cycle of 0.042nm/cycle and 0.056 nm/cycle, at 100–160 °C and 100–130 °C, respectively. Comparison of two tin-based thin film materials demonstrates dissimilar deposition features depending on the reactivity of the Sn precursors, i.e., Sn(dmamp)2 with anion sources provided by the water and hydrogen sulfide reactants. Density functional theory (DFT) calculations show that surface exchange reaction between *OH and *SH groups determine preference of S incorporation in the Sn(O,S) thin films. The material properties of ALD-based SnO, SnS, and Sn(O,S) thin films were characterized in terms of composition, stoichiometry, crystallinity, band structure, and electronic properties, demonstrating the potential of ALD SnO and SnS as p-type channel materials for transparent electronics.

Dependence of Photovoltaic Properties of Spray-Pyrolyzed F-Doped SnO2 Thin Film on Spray Solution Preparation Method

Spray pyrolysis deposition of SnCl2.2H2O- and NH4F-containing solution is an appropriate method for deposition of fluorine-doped tin oxide (FTO), which has extensive applications in photovoltaic devices. According to a literature review, several spray preparation methods have been studied. These methods lead to both precipitated and unprecipitated spray solutions. Precipitated and unprecipitated solutions were used for deposition of FTO thin films. FTO obtained from unprecipitated solution yielded the lowest sheet resistance and resistivity, which was due to its highest electron concentration (ne). However, precipitation had no influence on electron mobility. The x-ray diffraction patterns of precipitates showed the presence of Sn- and F-containing compounds, which implied partial depletion of F and Sn from solutions. As a result, a lower amount of F− ions was incorporated into FTO, which led to lower ne. In addition, partial depletion of Sn led to slightly smaller FTO thickness. Finally, FTO thin film deposited from unprecipitated solution gave the highest figure of merit. This means that precipitation in the precursor solution has deleterious effects on electrical and optical properties.

Effect of metal catalysts on the morphological and structural properties of tin oxide nanowires

In the present work, structural and morphological studies of grown tin oxide nanowires have been carried out with gold (Au), copper (Cu) and nickel (Ni) metals as catalysts. We have deposited tin oxide onto different metal catalysts (Au, Cu and Ni) coated silicon substrates through the thermal evaporation technique. The growth of tin oxide nanostructures on different catalysts has been analyzed at an optimized temperature. With the help of data of chemical and physical parameters of these catalysts, we developed a model which supports the experimental results for the growth of tin oxide nanowires. It has been found that among these catalysts, Ni shows highest aspect ratio nanostructure. Results are also supported by the optical studies.

Tetraallyltin precursor for plasma enhanced atomic layer deposition of tin oxide: Growth study and material characterization

In this letter, the authors report on the application of tetraallyltin (TASn) as an Sn-precursor for plasma enhanced atomic layer deposition (PEALD) of tin oxide (SnO2) thin films. The selection procedure for the TASn precursor is discussed. Tin oxide PEALD growth is shown to be self-limiting with a constant growth-per-cycle of 0.046 ± 0.002 nm/cycle in the substrate temperature (Tsub) range of 50–150 °C. Optical constants, chemical bonding, and electronic properties of as-grown PEALD films were characterized to evaluate the quality of tin oxide film obtained with the TASn precursor. A 21.6 nm tin oxide film grown at Tsub = 50 °C exhibited an indirect optical bandgap (Eg) of 2.94 eV and appeared amorphous from the glancing incidence x-ray diffraction pattern. Binding energy difference ΔBE(O1s, Sn3d5/2) = 43.77 eV and valence band emission in x-ray photoelectron spectroscopy showed that these were near-stoichiometric SnO2 with the relative O:Sn atomic ratio of 1.98 (or SnO1.98). Moreover, room temperature electrical resistivity ρele = 13.1 ± 1.6 mΩ cm, with electron concentration Ne = (3.78 ± 0.79) × 1019 cm−3 and Hall mobility μe = 13.2 ± 2.0 cm2 V−1 s−1, showed that electrical characteristics of the as-grown tin oxide films with the TASn precursor are comparable to those grown using other standard Sn precursors.

Ultraviolet detection properties of electrodeposited n-SnO2 modified p-Si nanowires hetero-junction photodiode

Highly dense, vertically aligned silicon nanowires (SiNWs), having diameters in the range of 40–100 nm and length upto 5 µm, are grown by metal assisted chemical etching technique on p-type polycrystalline silicon (pc-Si) substrate. The hetero-junction photodiodes, for ultraviolet sensing application, are fabricated by depositing tin oxide (n-SnO2) onto pc-Si and SiNWs on pc-Si surface, using simple and low cost electrochemical deposition technique. The prepared SiNWs and n-SnO2 decorated SiNWs are examined by scanning electron microscopy and elemental dispersive analysis by X-ray. Three photodiodes with device architectures Al/Ti/SiNWs/pc-Si/Ti/Al, Al/Ti/n-SnO2/pc-Si/Ti/Al and Al/Ti/n-SnO2/SiNWs/pc-Si/Ti/Al are fabricated and their UV sensing behavior is studied by recording their V–I characteristics under dark and UV-radiation. The recorded V–I curves of the fabricated devices show diode like behavior and their rectification ratio, turn on voltage, effective barrier height and sensitivity are calculated and compared. Under UV exposure, the V–I studies under forward and reverse biasing for the device Al/Ti/n-SnO2/SiNWs/pc-Si/Ti/Al shows significantly higher rectification ratio, sensitivity, responsivity and detectivity around 172.3 at ± 9 V, 64, 0.3456 A/W at 5 V and 8.02869 × 1012 Jones respectively. Further, the photo-resistive measurements of the device also show its excellent reproducible nature. This better UV sensing behavior is also supported with proposed UV sensing mechanism under biasing conditions.

Improved hole injection for blue phosphorescent organic light-emitting diodes using solution deposited tin oxide nano-particles decorated ITO anodes

Blue phosphorescent organic light-emitting diodes (PHOLEDs) were fabricated with tin oxide (SnOx) nano-particles (NPs) deposited at the ITO anode to improve their electrical and optical performances. SnOx NPs helped ITO to increase the work function enhancing hole injection capability. Charge balance of the device was achieved using p- and n-type mixed host materials in emissive layer and the devices’ luminance and maximum external quantum efficiency (EQE) increased about nearly 30%. Tuning the work function using solution processed NPs allows rapid optimization of device efficiency.

Low-Temperature Plasma-Enhanced Atomic Layer Deposition of Tin(IV) Oxide from a Functionalized Alkyl Precursor: Fabrication and Evaluation of SnO2-Based Thin-Film Transistor Devices.

A bottom-up process from precursor development for tin to plasma-enhanced atomic layer deposition (PEALD) for tin(IV) oxide and its successful implementation in a working thin-film transistor device is reported. PEALD of tin(IV) oxide thin films at low temperatures down to 60 °C employing tetrakis-(dimethylamino)propyl tin(IV) [Sn(DMP)4] and oxygen plasma is demonstrated. The liquid precursor has been synthesized and thoroughly characterized with thermogravimetric analyses, revealing sufficient volatility and long-term thermal stability. [Sn(DMP)4] demonstrates typical saturation behavior and constant growth rates of 0.27 or 0.42 Å cycle-1 at 150 and 60 °C, respectively, in PEALD experiments. Within the ALD regime, the films are smooth, uniform, and of high purity. On the basis of these promising features, the PEALD process was optimized wherein a 6 nm thick tin oxide channel material layer deposited at 60 °C was applied in bottom-contact bottom-gate thin-film transistors, showing a remarkable on/off ratio of 107 and field-effect mobility of μFE ≈ 12 cm2 V-1 s-1 for the as-deposited thin films deposited at such low temperatures.

The impact of indium tin oxide deposition and post annealing on the passivation property of TOPCon solar cells

In this paper, the influence of indium tin oxide (ITO) deposition on the passivation quality of tunnel oxide passivated contact solar cells was investigated. Both phosphorous-doped poly-Si/SiOx (n-TOPCon) and boron-doped poly-Si/SiOx (p-TOPCon) stacked films were fabricated on crystalline Si substrate, and ITO thin films were deposited by radio frequency (RF) magnetron sputtering system with various temperatures and RF powers, followed by post annealing. Effective minority carrier lifetime (τeff) of all the samples degraded drastically after ITO deposition. After post annealing, τeff of p-TOPCon samples exhibited significant recovery, while τeff of n-TOPCon samples only recovered partially. In addition, the deposition of ITO at lower RF power or room temperature leads to more effective recovery of τeff. The τeff recovery after ITO deposition thus depends on the types of TOPCon, which may be related to the film quality improvement of poly-Si during the post-annealing. The conversion efficiency of the top/rear TOPCon solar cells was decreased severely due to the sputtering damage during ITO deposition, and it can be improved by post-annealing at relatively high temperature.

Effect of ozone concentration on atomic layer deposited tin oxide

Tin dioxide (SnO2) thin films were deposited by atomic layer deposition (ALD) using tetrakis(dimethylamino)tin {[(CH3)2N]4Sn} and various concentrations of ozone (O3) at 200 °C. In order to characterize SnO2 thin films, the growth rate, thin film crystallinity, surface roughness, chemical bonding state, and electrical and optical properties were investigated. The growth rate of SnO2 increased slightly when the O3 concentration was increased. However, the growth rate was almost saturated above 300 g/m3 concentration of O3. Also, the x-ray diffraction patterns of SnO2 thin films become sharper when the O3 concentration increased. Specifically, the (101) and (211) peaks of SnO2 improved. In addition, the defects of the SnO2 thin films such as oxygen vacancy and hydroxyl group are related to the O3 concentration that was observed via x-ray photoelectron spectroscopy. As the O3 concentration is higher than 300 g/m3, the electrical Hall resistivity and mobility saturated 3.6 × 10−3 Ω cm and 9.58 cm2/V s, respectively. However, the carrier concentration slightly decreased to 3.22 × 1020 cm−3. It is assumed that the oxygen vacancies were filled with a high O3 concentration at ALD reaction. The optical bandgaps were larger than 3.5 eV, and the transmittance of all SnO2 thin films exceeded 90%. The O3 concentration below 200 g/m3 in the ALD process of SnO2 thin films is considered to be one of the factors that can affect the crystallinity, chemical bonding, and electrical properties.

Effect of F and Nb co-doping on structural, electrical and optical properties of spray deposited tin oxide thin films

F and Nb co-doped tin oxide films were deposited from monobutyltin trichloride (C4H9SnCl3) on glass substrates at 470 °C by spray pyrolysis. The evolution of the film structure and morphology was investigated by X-ray diffraction and scanning electron microscopy, respectively. All the films were a single phase with polycrystalline, exhibiting a tetragonal cassiterite structure with (200) orientation. The introduction of F and Nb contributed to the growth of the films towards (200) crystal orientation and the formation of pyramidal shape particles with (101) twin planes. Resistivity, carrier concentration, and Hall mobility values of 3.62 × 10−4 Ω cm, 7.463 × 1020 cm−3, and 27.8 cm2 V−1 s−1, respectively, were achieved in the films for a dopant concentration of 20 at.% F and 1 at.% Nb in the precursor solution. Also, the transmittance of all the films in the visible range reached about 80% and the infrared reflectivity was oscillated between 92 and 96%.

Spatial Atmospheric Pressure Atomic Layer Deposition of Tin Oxide as an Impermeable Electron Extraction Layer for Perovskite Solar Cells with Enhanced Thermal Stability.

Despite the notable success of hybrid halide perovskite-based solar cells, their long-term stability is still a key-issue. Aside from optimizing the photoactive perovskite, the cell design states a powerful lever to improve stability under various stress conditions. Dedicated electrically conductive diffusion barriers inside the cell stack, that counteract the ingress of moisture and prevent the migration of corrosive halogen species, can substantially improve ambient and thermal stability. Although atomic layer deposition (ALD) is excellently suited to prepare such functional layers, ALD suffers from the requirement of vacuum and only allows for a very limited throughput. Here, we demonstrate for the first time spatial ALD-grown SnOx at atmospheric pressure as impermeable electron extraction layers for perovskite solar cells. We achieve optical transmittance and electrical conductivity similar to those in SnOx grown by conventional vacuum-based ALD. A low deposition temperature of 80 °C and a high substrate speed of 2.4 m min-1 yield SnOx layers with a low water vapor transmission rate of ∼10-4 gm-2 day-1 (at 60 °C/60% RH). Thereby, in perovskite solar cells, dense hybrid Al:ZnO/SnOx electron extraction layers are created that are the key for stable cell characteristics beyond 1000 h in ambient air and over 3000 h at 60 °C. Most notably, our work of introducing spatial ALD at atmospheric pressure paves the way to the future roll-to-roll manufacturing of stable perovskite solar cells.

Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on–off ratio (5.2 × 106) and a low off-current (1.2 × 10−12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

Amorphous Tin Oxide as a Low-Temperature-Processed Electron-Transport Layer for Organic and Hybrid Perovskite Solar Cells.

Chemical bath deposition (CBD) of tin oxide (SnO2) thin films as an electron-transport layer (ETL) in a planar-heterojunction n-i-p organohalide lead perovskite and organic bulk-heterojunction (BHJ) solar cells is reported. The amorphous SnO2 (a-SnO2) films are grown from a nontoxic aqueous bath of tin chloride at a very low temperature (55 °C) and do not require postannealing treatment to work very effectively as an ETL in a planar-heterojunction n-i-p organohalide lead perovskite or organic BHJ solar cells, in lieu of the commonly used ETL materials titanium oxide (TiO2) and zinc oxide (ZnO), respectively. Ultraviolet photoelectron spectroscopy measurements on the glass/indium-tin oxide (ITO)/SnO2/methylammonium lead iodide (MAPbI3)/2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene device stack indicate that extraction of photogenerated electrons is facilitated by a perfect alignment of the conduction bands at the SnO2/MAPbI3 interface, while the deep valence band of SnO2 ensures strong hole-blocking properties. Despite exhibiting very low electron mobility, the excellent interfacial energetics combined with high transparency (Egap,optical > 4 eV) and uniform substrate coverage make the a-SnO2 ETL prepared by CBD an excellent candidate for the potentially low-cost and large-scale fabrication of organohalide lead perovskite and organic photovoltaics.

Transparent Conductive Oxide Films for High-Performance Dye-Sensitized Solar Cells

In this paper, atmospheric pressure chemical vapor deposition of fluorine-doped tin oxide (FTO) thin films of various thicknesses and dopant levels is reported. The deposited coatings are used to fabricate dye-sensitized solar cells, which exhibited reproducible power conversion efficiencies in excess of 10%. No surface texturing of FTOs or any additional treatment of dye-covered films is applied. In comparison, the use of commercial FTOs showed a lower cell efficiency of 7.11%. Detailed analysis showed that the cell efficiencies do not simply depend on the resistivity of FTOs but instead rely on a combination of carrier concentration, thickness, and surface roughness properties.

Atomic layer deposition of tin oxide using tetraethyltin to produce high-capacity Li-ion batteries

The authors deposited thin films of tin oxide on substrates of silicon and stainless steel by using atomic layer deposition (ALD) with tetraethyltin precursors. In this process, the authors used various coreactants such as water, oxygen, remote oxygen plasma, hydrogen peroxide, and ozone. The growth rates of films were studied as functions of the deposition temperature, the pulse times of the precursor and coreactant, and the number of ALD cycles, and the optimal growth conditions were determined. The film growth rates were found to be 0.025, 0.045, and 0.07 nm per cycle within the optimal growth conditions and ALD temperature windows for H2O2, O3, and O2 plasma, respectively. Using H2O or O2 did not prompt film growth. The films deposited using O3 and H2O2 had good continuity and low roughness, while the morphology of a coating prepared using oxygen plasma depended greatly on the deposition temperature. The films produced at temperatures below 300 °C were amorphous, irrespective of the coreactant used. X-ray photoelectron spectroscopy revealed that the samples mainly contained tin in the +4 oxidation state. The films deposited on stainless steel had high reversible capacity above 900 mA h g−1, exceptional cycleability, and good electrochemical performance as anodes for lithium-ion batteries.

Deposition by Spray-Pyrolysis of Tin Oxide Doped with Fluorine Produced by Sol-Gel Method

Solar energy is one of the most important sources of renewable energy today. The production of electric energy is based on silicon cells, which are expensive and difficult to produce and therefore, New preparation methods, materials or approaches are needed. This work aims to deposit Tin oxide doped with fluorine, prepared by sol-gel, on a glass substrate using the spray pyrolysis technique. F-SnO2 (FTO) solution was synthesized by sol-gel method, employing NH4F and SnCl2 precursors in an ethanol solution. Before the formation of the gel, the solution was sprayed using a pistol aerographic, On a substrate at approximately 600oC. This process was repeated 50 times, and after that, the sample was cooled until room temperature inside the furnace. The obtained samples (substrates for the PV cell) present a resistance between 10 and 30 Ω. The energy dispersive x-ray (EDS) was used to confirm the presence of fluorine in the SnO2 network.