Tin Oxide Layer Research Articles

Investigation of Electrochromic, Combinatorial TiO2-SnO2 Mixed Layers by Spectroscopic Ellipsometry Using Different Optical Models.

We determined the optimal composition of reactive magnetron-sputtered mixed layers of Titanium oxide and Tin oxide (TiO2-SnO2) for electrochromic purposes. We determined and mapped the composition and optical parameters using Spectroscopic Ellipsometry (SE). Ti and Sn targets were put separately from each other, and the Si-wafers on a glass substrate (30 cm × 30 cm) were moved under the two separated targets (Ti and Sn) in a reactive Argon-Oxygen (Ar-O2) gas mixture. Different optical models, such as the Bruggeman Effective Medium Approximation (BEMA) or the 2-Tauc-Lorentz multiple oscillator model (2T-L), were used to obtain the thickness and composition maps of the sample. Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDS) has been used to check the SE results. The performance of diverse optical models has been compared. We show that in the case of molecular-level mixed layers, 2T-L is better than EMA. The electrochromic effectiveness (the change of light absorption for the same electric charge) of mixed metal oxides (TiO2-SnO2) that are deposited by reactive sputtering has been mapped too.

Multifunctional Metal-organic Frameworks Capsules Modulate Reactivity of Lead Iodide toward Efficient Perovskite Solar Cells with Ultraviolet Resistance.

The two-step sequential deposition process is demonstrated as a reliable technology for the fabrication of efficient perovskite solar cells (PVSCs). However, the complete conversion of dense PbI2 to perovskite in planar PVSCs is tough without mesoporous titanium dioxide as support. Herein, multifunctional capsules consisting of zeolitic imidazolate framework-8 (ZIF-8) encapsulant and formamidinium iodide (FAI) are introduced between tin oxide (SnO2 ) and lead iodide (PbI2 ) layer. Intriguingly, the capsule dopant interlayer benefits the formation of porous PbI2 film due to the porous nanostructure of ZIF-8 which is favorable for the subsequent intercalation reaction. Furthermore, the constituent of the perovskite precursor in ZIF-8 pores can convert into the crystal nuclei of perovskite by reacting with PbI2 first, thereby promoting further perovskite crystallization. Significantly, the incorporation of ZIF-8 can enhance the resistance of perovskite against ultraviolet (UV) illumination due to down-conversion effect. Consequently, the modified device achieves a champion power conversion efficiency (PCE) of 24.08% and displays enhanced UV stability, which can sustain 83% of its original PCE under 365nm UV illumination for 300h. Moreover, the unencapsulated device maintains 90% of initial PCE after 1500h storage in dark ambient conditions with a relative humidity range of 50∼70%. This article is protected by copyright. All rights reserved.

Effect of oxygen flow rate on properties of multilayer aluminum-doped indium saving ITO thin films produced by sputtering method

Multilayer aluminum-doped indium saving indium-tin oxide (ITO) thin films with low volume resistivity and high transmittance in the visible spectrum have been designed and fabricated by sputtering method. Double-layered structures consisting of very thin layer of conventional indium tin oxide (In2O3-10 mass % SnO2) and aluminum-doped indium saving indium-tin oxide layer with reduced to 50 mass % In2O3 content are discussed. Multilayer aluminum-doped ITO were deposited on glass substrates preheated at 523 K. Thin films deposited in pure argon demonstrate volume resistivity of 445 µΩcm, mobility of 26 cm2/V·s, carrier concentration of 5.6 × 1020 cm−3 and average transmittance larger than 85% in the visible range. Introducing oxygen to sputtering gas allowed increasing average transmittance of as-deposited multilayer aluminum-doped indium saving ITO thin films over 90% in the visible range. As-deposited multilayer aluminum-doped ITO thin films showed significantly higher transmittance in comparison with undoped ML ITO50/ITO90 and crystallized in In4Sn3O12 structure.

Interface engineering of Tin(IV) oxide electron transport layer with Yttrium(III) fluoride for efficient carbon-based perovskite solar cells

Carbon-based perovskite solar cells (C–PSCs) are the most promising technology to meet global energy demands at a reasonable price. In the current study, to assemble efficient and stable C–PSCs, the interface between the tin oxide electron transport layer and the mixed-cation perovskite layer was tailored by coating yttrium fluoride (YF3) material over the tin oxide layer. Results show that YF3–SnO2 ETL produces a more suitable substrate for perovskite fabrication, causing the formation of a perovskite layer with enlarged grains and a lower PbI2 residual. In addition, the results indicate that YF3 treatment could boost the conductivity of SnO2, reduce defects in the mixed-cation perovskite layer, and suppress nonradiative recombination in the C–PSCs. YF3-based interface engineering brought champion C–PSCs with an efficiency of 14.01% under simulated illumination of 100 mW cm−2, which was considerably higher than the 11.58% recorded for control C–PSCs. After 168 days of aging, the unsealed, modified C-PSC devices can demonstrate superior ambient air stability behavior conditions and retain 95% of their initial performance.

Enhanced optoelectronic and supercapacitive performance of electrodeposited Mn3O4 thin film prepared from two-electrode: An effect of Zn-ion incorporation

Here in, we report electrodeposited Mn3O4 thin film doped with various level of Zn dopant (0≤x≤5.0,%), on a layer of indium tin oxide (ITO) on glass substrate. The deposition route involves the use of two-electrode electrochemical cell system comprising graphite and the substrate as counter and working electrodes, respectively. Some surface properties such as those of morphological, crystal structure, optical, electrical and electrochemical were studied to evaluate the films’ potentials in energy conversion and storage devices. Microstructural studies revealed the films grew with isotropic morphology of good tetragonal shaped crystal structure with even distribution and possessing required surface area on the substrate surfaces. Raman prominent peak at 659 cm −1 wave number indicates a typical A1g Raman vibrating mode of Mn2+ in a Mn3O4 spinel structure. The crystallite size and microstrain values were found varying from 38 to 43 nm and 5.6 × 10−3 to 3.2 × 10−3, with respect to increase in dopant content, respectively. Energy band gap and Urbach energy were varied from 3.28 to 2.68 eV and 1.59 to 2.17 eV with increasing level of dopant content, accordingly. Electrochemical charge storage area capacitance (12.62 to 21.35 mF cm −2)/capacity (5.1 to 8.1μAh cm −2) and rate capability of Mn3O4 electrode were found to improve with Zn dopant. The work therefore discusses the tailoring of band absorption and supercapacitive characteristic of electrodeposited Mn3O4 thin film with Zn-doping for enhanced energy application.

Constructing a Multifunctional Interlayer toward Ultra‐High Critical Current Density for Garnet‐Based Solid‐State Lithium Batteries

AbstractAll‐solid‐state lithium batteries (ASSLBs), exhibiting great advantages of high energy density and safety, are proposed to be the next generation energy storage system. However, the successful commercialization of garnet‐based ASSLBs is hindered by the poor contact between solid‐state electrolytes (Li6.25Ga0.25La3Zr2O12, LGLZO) and lithium anode, as well as low critical current density (CCD). Herein, an indium tin oxide (ITO) layer is prepared on LGLZO by ultrasonic spraying technique, where ITO reacts with molten lithium to form a composite interlayer, consisting of Li13In3, Li2O, and LiInSn. Experiments and density functional theory calculations demonstrate that such a unique interlayer plays a multifunctional role in achieving simultaneously better interface wettability, uniform Li deposition, and dendrite suppression at Li/LGLZO interface. Consequently, the CCD of ITO‐treated symmetric cell is increased to a record‐high value of 12.05 mA cm−2 at room temperature, which is expected to promote practical application of ASSLBs. Moreover, the Li/ITO@LGLZO/Li cell exhibits a low interfacial resistance of only 5.9 Ω cm2 and performs stable electrochemical operations for over 2000 h at 2 mA cm−2. The Li/ITO@LGLZO/LiFePO4 full cell also delivers superior electrochemical performances, demonstrating the efficiency of the ITO layer.

The effect of the crystallization of indium tin oxide on indium tin oxide wet etching based on gate line with the structure of copper/indium tin oxide

AbstractIn thin film transistor‐liquid crystal display (TFT‐LCD), the copper/indium tin oxide (Cu/ITO) layer was often used to be gate line. In this event, the patterning of ITO is necessary and important. However, the high temperature generated during Cu deposition will cause ITO to crystallize, which is not conducive to ITO etching. In this paper, the ITO films prepared by radio frequency (RF) magnetron sputtering were annealed according to the monitoring results of production line to simulate and study the effect of crystallization on the etching properties of ITO film. When the annealing temperature was less than 200°C, no large size grains were detected in ITO films, and the ITO films could be easily etched by etchant. However, the ITO films transformed from amorphous structure to polycrystalline structure after being annealed more than 200°C. After wet etching experiments, the polycrystalline ITO films could be hardly removed by etchant. The X‐ray photoelectron spectroscopy (XPS) results showed that high temperature annealing induced a large amount of Sn4+ on ITO films surface. The Sn4+ was difficult to be dissolved by acid under normal conditions, which might be the most important factors that led to the greatly decreased etching rate for polycrystalline ITO films.

Time-varying gradient metasurface with applications in all-optical beam steering

Abstract Integrating the large, subpicosecond nonlinear optical response of epsilon-near-zero (ENZ) materials with the broad design freedoms of plasmonic metasurfaces shows potential for creating rapidly modulated optical devices with possible applications in telecommunications, sensing, and reactive beam steering. In this work, we experimentally investigate a metasurface consisting of a plasmonic gradient array on a thin layer of indium tin oxide (ITO), characterize how incident probe pulses diffract from a system as it is being dynamically modulated by a pump pulse at wavelengths near the ENZ region. Angular shifts in the diffraction orders are observed and can be principally attributed to the adiabatic wavelength conversion of the probe as it witnesses the temporal change of index induced by the pump. Of note, the asymmetric gradient metasurface, considered to be a blazed diffraction grating, shows significantly different dynamic responses for different diffraction orders. The free-space wavelength shift to +1 and −1 diffraction orders is 6 and 12 nm, resulting in steering angle changes of 0.65 and 1.5°, respectively.

Encapsulation of tin oxide layers on gold nanoparticles decorated one-dimensional CdS nanoarrays for pure Z-scheme photoanodes towards solar hydrogen evolution

Despite their high potential for solar energy conversion into chemical fuels, most artificial all-solid-state Z-scheme photosystems have disordered structures and focus on power photocatalytic water splitting applications rather than photoelectrochemical (PEC) cells. Herein, an innovative pure Z-scheme heterostructure, CdS/Au/SnO2-S, composed of one-dimensional (1D) oriented CdS nanorods modified with SnO2-wrapped Au nanoparticles (NPs), was designed as a photoanode for highly efficient PEC hydrogen evolution. Systematic characterization confirms that the incorporated Au NPs not only act as the host platform to support the SnO2 layer growth but also play a key role as the electron mediator for strengthening the vectorial charge transfer from SnO2 to CdS. This reinforced Z-scheme charge transportation channel is favorable for suppressing the bulk charge recombination process, increasing the overall carrier density, and preserving the strong redox capability, ultimately resulting in a considerably improved photocurrent density and photo-to-current conversion efficiency with better corrosion resistance.

Voltage-Dependent FTIR and 2D Infrared Spectroscopies within the Electric Double Layer Using a Plasmonic and Conductive Electrode.

Strong electric fields exist between the electric double layer and charged surfaces. These fields impact molecular structures and chemistry at interfaces. We have developed a transparent electrode with infrared plasmonic enhancement sufficient to measure FTIR and two-dimensional infrared spectra at submonolayer coverages on the surface to which a voltage can be applied. Our device consists of an infrared transparent substrate, a 10-20 nm layer of conductive indium tin oxide (ITO), an electrically resistive layer of 3-5 nm Al2O3, and a 3 nm layer of nonconductive plasmonic gold. The materials and thicknesses are set to maximize the surface number density of the monolayer molecules, electrical conductivity, and plasmonic enhancement while minimizing background signals and avoiding Fano line shape distortions. The design was optimized by iteratively characterizing the material roughness and thickness with atomic force microscopy and electron microscopy and by monitoring the plasmon resonance enhancement with spectroscopy. The design is robust to repeated fabrication. This new electrode is tested on nitrile functional groups using a monolayer of 4-mercaptobenzonitrile as well as on CO and CC stretching modes using 4-mercaptobenzoic acid methyl ester. A voltage-dependent Stark shift is observed on both monolayers. We also observe that the transition dipole strength of the CN mode scales linearly with the applied voltage, providing a second way of measuring the surface electric field strength. We anticipate that this cell will enable many new voltage-dependent infrared experiments under applied voltages.

Reducing Nonradiative Losses in Perovskite LEDs through Atomic Layer Deposition of Al2O3 on the Hole-Injection Contact.

Halide perovskite light-emitting diodes (PeLEDs) exhibit great potential for use in next-generation display technologies. However, scale-up will be challenging due to the requirement of very thin transport layers for high efficiencies, which often present spatial inhomogeneities from improper wetting and drying during solution processing. Here, we show how a thin Al2O3 layer grown by atomic layer deposition can be used to preferentially cover regions of imperfect hole transport layer deposition and form an intermixed composite with the organic transport layer, allowing hole conduction and injection to persist through the organic hole transporter. This has the dual effect of reducing nonradiative recombination at the heterojunction and improving carrier selectivity, which we infer to be due to the inhibition of direct contact between the indium tin oxide and perovskite layers. We observe an immediate improvement in electroluminescent external quantum efficiency in our p-i-n LEDs from an average of 9.8% to 13.5%, with a champion efficiency of 15.0%. The technique uses industrially available equipment and can readily be scaled up to larger areas and incorporated in other applications such as thin-film photovoltaic cells.

Inside the ovonic threshold switching (OTS) device based on GeSbSeN: Structural analysis under electrical and thermal stress

In this article, we present the structural investigation by Raman spectroscopy of GeSbSeN ovonic threshold switching (OTS) material once integrated in selector devices featuring a top electrode based on a transparent and conductive indium tin oxide layer. The devices are characterized by standard electrical protocols, and the structural evolution of the material is investigated after several switching operations. The results are correlated with the spectra obtained from blanket samples annealed at increasing temperature and are supported by XRD and TEM analyses. We establish a link between the evolution of the material structure with the annealing process and the device behavior along cycling, bringing important advancement in the understanding of the switching mechanism and of the origin of the failure in OTS devices.

Importance of the Buffer Layer Properties for the Performance of Perovskite/Silicon Tandem Solar Cells

The power conversion efficiency of two-terminal perovskite/silicon tandem solar cells recently surpassed 30%, demonstrating the great potential of this technology. The most common electron-selective contact is a stack of a buckminsterfullerene film, a tin oxide buffer layer, and a transparent conductive oxide. While research is conducted on improving the fullerene/perovskite interface and on removing the buffer layer, less focus is put on tuning the buffer layer properties. In this work, the interplay of the doping densities in the fullerene film and the tin oxide layer as well as the impact of the tin oxide electron affinity on the device performance is investigated using electrical numerical simulations (technology computer-aided design). The simulated power conversion efficiency increases with higher doping densities in the fullerene film and the tin oxide layer, while an increasing conduction band offset between the two materials leads to a decreasing device performance. The results of this work imply that the properties of the buffer layer directly influence the performance of the tandem solar cell. In addition, the importance of measuring various material and interface characteristics in order to derive an improved device understanding is stressed.

The effect of electrolyte temperature on the growth, morphology, and properties of porous anodic tin oxide films

The effect of electrolyte temperature on the anodic formation of nanoporous tin oxide layers, their morphology and properties was studied in detail. Electrochemical synthesis of SnOx films was carried out in both acidic (H2C2O4) and alkaline (NaOH) electrolytes at various potentials. Differences in morphological features of as-generated films and the kinetics of their formation were carefully investigated from FE-SEM images. The effect of anodizing temperature was successfully verified revealing its undeniable importance when designing the anodization procedure. For instance, both in acidic and alkaline electrolytes, applying too low temperatures results in formation of cracked oxide layers with the least open pores or compact surface, while too high temperatures (≥40 °C) leads to obtaining films with clogged pores due to the partial etching of the material by the electrolyte. Anodizing temperature was also found to be a crucial parameter responsible for the type of morphology of the synthesized materials (compact or porous layers or even crater-like hierarchical structures) when the process is carried out at higher potentials (here 9 V). Finally, we have proved that the impact of electrolyte temperature on the crystallinity of the anodic tin oxide layers is negligible, whereas the photoelectrochemical activity is significantly influenced due to the tight relation with the morphology of as-synthesized materials.

Characteristics of High-Power Impulse Magnetron Sputtering ITO/Ag/ITO Films for Application in Transparent Micro-LED Displays

In this study, a blue transparent micro-LED display with a chip size of 20 μm × 20 μm, a pixel density of 152 PPI, a pixel spacing of 150 μm, and a resolution of 64 × 32 has been fabricated. ITO/Ag/ITO transparent layers were deposited by high-power impulse magnetron sputtering. Sheet resistance was used to analyze the electrical properties of the indium tin oxide (ITO) layers, whereas scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to examine the surface morphology. These results demonstrate that the ITO/Ag/ITO structure with 20 nm thick Ag has a lower sheet resistance (3.36 Ω/sq) and sufficient visible light transmittance (80.45%). The visible light transmittance of the ITO/Ag/ITO layers increased to 86% after rapid thermal annealing. In addition, surface roughness was minimized, and sheet resistance was further reduced, resulting in ohmic contact on n-GaN that is suited for applications involving transparent micro-LED displays.

Simple electrically tunable liquid crystal spatial phase modulator.

We describe multiple optical functionalities obtained with a simple electrically tunable liquid crystal element that can be controlled by 4 electrodes, which are connected to a serpentine shaped transparent indium tin oxide layer. We experimentally demonstrate that the device is capable of dynamically generating refractive index distributions corresponding to a standard spherical lens, axicon, cylindrical lens, and prism. The dynamic switching of the device between these different operation modes is done in a very simple electronic way. We think that this element has a significant potential for applications in adaptive imaging, optogenetics, photonic integrated circuits, etc.

Understanding Silicon Heterojunction Solar Cells with nc‐SiC/SiO2as an Alternate Transparent Passivating Front Contact and Computational Design Optimization

The potential performance of silicon heterojunction solar cells applying transparent passivating contact (TPC) at the front side, based on a nc‐SiC:H/SiO2layer stack, is modeled and investigated. Herein, a complete multiscale electro‐optical device model of TPC solar cells is developed. The model is then used to understand and analyze such cells and search for potential conversion efficiency improvement paths. The influences of contact layer thicknesses and other properties on device performance are studied. An algorithm‐based optimization of cell electro‐optical performance is performed. It is implemented by coupling a genetic algorithm with a finite element method‐based TPC solar cell device model. Optimum front contact layer thicknesses are calculated. For optically optimized TPC contact layer thicknesses, an optical improvement of around 0.5 mA cm−2is found. Moreover, for complete electro‐optical optimization of TPC layers, about 0.27% absolute value increment in power conversion efficiency is calculated. At the rear side, proper designing of optimizing carrier transport using active dopant concentration of p‐type a‐Si:H layer and indium tin oxide layer has shown a potential to reach power conversion efficiency beyond 25%.

Ultrathin SnO2 electron transport layers for perovskite solar cells by combustion method at low temperature

Electron transport layers can collect photo-generated electrons and suppress interfacial recombination, which are crucial for efficient perovskite solar cells. Tin oxide is a suitable electron transport material for its wide bandgap, high electron mobility, low photocatalytic activity and appropriate energy band offsets. For the deposition of tin oxide layers, SnCl2 precursor is usually used for the conventional solution spin-coating method. In this work, we developed an in-situ synthesized precursor, and ultrathin tin oxide layers were obtained by the combustion process at 150 °C. Furthermore, the devices with these tin oxide layers can achieve the PCE of 19.6%, while conventional tin oxide layers with SnCl2 precursor lead to the PCEs of 16.9% and 14.9% with and without plasma treatment. This improvement can be related to the enhanced photoelectron collection and superior interfacial contact. This work provides a facile method for fabricating SnO2 electron transport layers of perovskite solar cells at low temperature.

Spectromicroscopy Studies of Silicon Nanowires Array Covered by Tin Oxide Layers.

The composition and atomic and electronic structure of a silicon nanowire (SiNW) array coated with tin oxide are studied at the spectromicroscopic level. SiNWs are covered from top to down with a wide bandgap tin oxide layer using a metal-organic chemical vapor deposition technique. Results obtained via scanning electron microscopy and X-ray diffraction showed that tin-oxide nanocrystals, 20nm in size, form a continuous and highly developed surface with a complex phase composition responsible for the observed electronic structure transformation. The "one spot" combination, containing a chemically sensitive morphology and spectroscopic data, is examined via photoemission electron microscopy in the X-ray absorption near-edge structure spectroscopy (XANES) mode. The observed spectromicroscopy results showed that the entire SiNW surface is covered with a tin(IV) oxide layer and traces of tin(II) oxide and metallic tin phases. The deviation from stoichiometric SnO2 leads to the formation of the density of states sub-band in the atop tin oxide layer bandgap close to the bottom of the SnO2 conduction band. These observations open up the possibility of the precise surface electronic structures estimation using photo-electron microscopy in XANES mode.

Realization of tuneable ultrabroadband interconnection for solitonic-plasmonic synapsis by exploiting epsilon near zero conducting oxides

This research introduces a novel highly efficient method to interconnect two metallic nanostrips that support the propagation of surface plasmon polariton (SPP) waves exploiting photorefractive soliton guide. The intricate design of the multilayer geometry enables light control diffraction at the metallic nanostrip’s end and reduces its angular dispersion. Moreover, the system’s on/off state can be switched by exploiting the epsilon near zero properties of the indium tin oxide (ITO) layer. The photorefractive crystal positioned between the two plasmonic waveguides enables the self-confinement of light, generating a waveguide that can be utilized by both the writing light and other wavelengths transmitted as signals. The resulting SPP waves can be efficiently recoupled in the second nanostrip, with an efficiency of around 40% across a broad range of wavelengths. This cutting-edge approach paves the way for significant advancements in the field of nanophotonics and provides a fundamental framework for the development of new, highly efficient optical interconnects in nanoscale systems. The findings of this study have implications for a wide range of applications, including nanoscale sensing, optical computing, and data communication.