Tin Oxide Materials Research Articles

Crystal facet‐controlled CeO2 as surface decoration on nanosheet‐type SnO2 for sensing ultralow concentration gases

AbstractImproving the gas‐sensing properties of sensors is important for the detection of ultralow‐concentration gases. As sensor signals are generated from the reactions on the surface of the sensor material, improving the surface structure of the sensor material can enhance the sensing properties. In this study, nanosheet‐type tin oxide with a metastable (101) crystal facet surface was used as the gas sensor material. To enhance the sensing properties, crystal facet‐controlled cerium oxide with superior oxygen storage capacity at moderate temperatures was decorated on the surface of the nanosheet‐type tin oxide material. An investigation of the sensor properties revealed that the decorated sensor exhibited improved gas selectivity and enhanced sensitivity to all tested gases. Prior to decoration, selectivity was observed for acetone and ethanol, whereas the decorated sensor exhibited high selectivity for acetaldehyde. The limits of detection of the decorated sensors were 245, 459, and 934 ppt for acetone, ethanol, and acetaldehyde, respectively. Thus, the proposed material can effectively enhance the sensing of extremely low‐concentration gases.

Construction of low-symmetrical charge-neutral Sn12-oxo football cage with the functionalized ligand

Tin-oxo clusters, as molecular model compounds of tin oxide materials, have attracted increasing attention. Although various tin-oxo clusters have been obtained, the systemic studies on ligand functionalization of tin-oxo clusters remain to be well developed. In this study, we adopted 3-aminopyrazine-2-carboxylic acid (HAPZC) as the functionalized ligand, and successfully synthesized a novel tin-oxo cluster [(n-BuSn)12(OH)6O14 (APZC)2]·2H2O (CTGU-SnC-3). Due to the functionalization of the APZC ligands, the structure and charge of Sn12 cage in CTGU-SnC-3 are all different from those of reported cationic football cage. This Sn12 cage in CTGU-SnC-3 presents the interesting low-symmetrical football framework with the functionalized ligands. Different from the reported cationic football cages, the CTGU-SnC-3 is charge-neutral structure without any counteranions. Moreover, the CTGU-SnC-3 exhibits hydrophobic behavior and catalytic activity in electrocatalytic CO2 reduction reaction.

Vortex harmonic generation in indium tin oxide thin film irradiated by a two-color field.

When a two-color Laguerre-Gaussian laser beam propagates through an indium tin oxide (ITO) material, the spatial distributions of odd- and even-order vortex harmonics carrying orbital angular momentum (OAM) are studied. The origin of vortex harmonics can be directly clarified by investigating their dependence on the incident laser field amplitude and frequency. In addition, it is shown that the spectral intensities of vortex harmonics are sensitive to the epsilon-near-zero nonlinear enhancing effects and the thickness of ITO materials. Thus the vortex harmonics can be conveniently tunable, which provides a wider potential application in optical communications based on high-order OAM coherent vortex beams.

Tin oxide as a Q‐switcher in an Nd‐doped fiber laser

AbstractA 1089 nm Q‐switched laser has been successfully developed by using a neodymium‐doped fiber (NDF) as a gain medium and tin oxide (SnO2) material as a saturable absorber (SA). The SnO2 SA was obtained by embedding the compound into a polyvinyl alcohol (PVA) host polymer so that it can be easily integrated into an NDF laser (NDFL) configuration to modulate the cavity loss for pulsing operation. The laser output pulse duration and repetition rate changed from 6.7 to 4.2 µs and from 55.8 to 72.5 kHz, respectively, when the 808 nm pumping power increased from 160.0 to 252.7 mW. The laser exhibited a stable output since we recorded a signal‐to‐background noise ratio of 46.4 dB. We believe that this work is the first to address SnO2 as SA in an NDFL cavity.

A fluorinated greenhouse gas sensor based on N-doped tin oxide materials

A novel N-doped tin oxide semiconductor metal oxide sensor has been successfully fabricated for fluorinated greenhouse gas sensing.

Characterization of Nanostructured Tin Oxide Anodes Obtained By Electrolytic Oxidation for High-Energy Lithium-Ion Batteries

In recent years, the growing electric vehicle market has increased the need for cost efficient and high energy materials for batteries drastically. Tin and tin oxide materials bear great potential as anode materials for Li-Ion batteries due to low cost and high theoretical capacity. Nevertheless, the development of commercial tin anodes has so far been hindered due to several drawbacks related to high volume expansion during operation leading to fast cell degradation. To circumvent these issues, nanostructured electrodes can be applied to mitigate volume changes. Typically, the production process of such electrodes is challenging, leading to high cost and issues in terms of scalability. Electrochemical processes, such as the electrolytic oxidation of tin, has been found a promising alternative to fabricate nanostructured electrodes. The additive-free tin oxide anodes obtained from this process exhibit high gravimetric and volumetric capacity, excellent rate capability as well as promising cycle life. The morphology and microstructure have high impact on the rate capability and cycling stability of tin oxide anodes. Since structural properties can be precisely adjusted by controlling the electrochemical oxidation process, a deeper understanding of the structure-property relationship is needed to optimize the production process and pave the way for commercialization.Herein an in-depth characterization of nanostructured tin oxide anodes formed by electrochemical oxidation is presented. The rate capability and the cycling stability are investigated by means of electrochemical measurements in battery cells. Operando electrochemical dilatometry is used to investigate the thickness change of the anodes during cycling (cell breathing). In-situ XRD measurements are applied to elucidate the reaction mechanism. The anodes are carefully analyzed by SEM/EDS at different state of lithiation to understand the impact of volume changes on the inner porosity and morphology. Finally, the cycling stability of tin oxide anodes is improved by applying an electrochemical prelithiation step. Therefore, the impact of different prelithiation regimes on the cycling stability is evaluated in full cells. The results contribute to the understanding of electrochemical behavior of nanostructured tin oxide anodes and the derivation of optimal design criteria adjusted by electrochemical surface engineering.

Graphene as advanced applied material in flexible display applications

Flexible display technology has grown in popularity as a study area in the electronics industry as a result of the quick development of flexible electronics technology. Transparent electrodes, the main element of flexible display technology, are crucial for high resolution, high brightness, low power consumption, and interference resistance. A new kind of transparent electrode material is urgently required because conventional applied transparent electrode materials have issues like expensive cost, difficult preparation, and low dependability. Due to its exceptional performance in terms of transparency, electrical conductivity, and flexible bendability, graphene has gained a much interest as an emerging material. In order to provide guidance on the future development of cutting-edge materials for flexible display applications, this paper investigates the use of graphene in flexible displays. It examines graphene's use as a transparent electrode material and a thin film transistor material in flexible displays, as well as its application prospects and development trends. It is found that graphene has a high transparency of 97.7% and high conductivity, which outperforms the generally used indium tin oxide and copper materials. However, further advancements in the mass production of graphene is necessary for the industrialization of graphene in flexible display applications.

LPDA-inspired Material-Geometry joint wide-angle broadband absorption based on metapyramid

The rapid development of metamaterials offers a new avenue to achieve exotic electromagnetic properties, such as perfect absorption for important stealth engineering applications. So far, there are few demonstrations of wide-angle broadband absorption, due to the stringent impedance matching requirement. Here, inspired by the concept of log-periodic dipole antenna (LPDA) for broadband emission, we propose a wide-angle broadband absorption based on both indium tin oxide (ITO) material and judiciously engineered metapyramid geometry. The strip ITO arrays on the sidewalls of metapyramid follow the quasi-LPDA strategy for gradient impedance and expands significantly both angular and spectral operating bandwidth by a cascading of multiple electric and magnetic resonances, as revealed by the rigorous characteristic mode analysis. Our experimental results show that the exotic absorption reaches above 0.9 at 45° tilted incidence for both transverse electric and transverse magnetic polarizations across the band of 8 ∼ 18 GHz. Our strategy circumvents the issues of limited-angle operation, high costs and high weight raised by metal structures, providing a new paradigm toward wide-angle broadband metadevices.

One-step spin-coating of methylammonium lead iodide on SILAR-deposited tin oxide, SnO2 films for effective electron transport

Tin oxide (SnO2) materials were prepared via successive ionic layer adsorption and reaction (SILAR) technique at varying deposition times. The synthesized tin oxide layer served as an electron transport layer for the deposition of a perovskite layer via spin coating method. The morphology, structure, elemental, optical features and vibration modes of the prepared samples have been studied using scanning electron microscopy (SEM), X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy (EDX), UV–vis spectrophotometry, and Raman spectrophotometry, respectively. The films revealed granular-shaped nanograins with a maximum average grain size of 197.03 nm. XRD results showed a cassiterite pure-phase crystal structure with several prominent peaks. EDX studies confirmed the as-deposited elemental constituents with good optical properties obtained from the optical studies. The band gap energies ranged from 4.01 to 4.24 eV at increasing deposition times. The phonon modes and crystal structures were also revealed from the Raman studies. The materials find applications in solar cells and electronic devices.

A flexible and transparent pliers shaped antenna for ultra-wideband applications

Flexible transparent antennas have broad potential applications in wireless communication and RF energy harvesting, providing visualization, small size, and integration functions for electronic devices. The use of optically transparent materials is an essential direction in the development of flexible transparent antennas. In this paper, a flexible and transparent antenna is designed by indium tin oxide material and photolithography process, which is suitable for wideband communication field. The broadband characteristics of the antenna are realized by using irregular slots and rectangular microstrip lines on the ground plane. The antenna operates in the frequency range of 1.73–20 GHz with a relative bandwidth of 168%, which is suitable for ultra-wideband (UWB) applications. The antenna has a compact structure and the relative size of 0.33 λ 0 × 0.28 λ 0. The measured results of the antenna are in good agreement with the simulated results, and the bending and folding tests show that the antenna has good mechanical flexibility and can cover the surface of irregular objects. This pliers-shaped antenna is applicable to a variety of UWB and wireless applications, such as LTE, Wi Max, 5G network, IoT, WIFI, mobile phone keys, and mobile payment.

Nanocomposite Electrodes and Membranes for PEM Electrolysis

Reducing the iridium loading while keeping high mass activity and durability is one of the greatest challenges for PEMWE development.[1] Amongst the strategies to achieve this central goal, supporting iridium oxide on metal oxide supports offers high resistance to corrosion as well as electronic electrocatalyst-support interactions beneficial for catalyst activity and durability.[2] The morphology of the supports also plays a crucial role in the control of architecture and porosity of the catalyst layers.Here, tin oxide materials doped with aliovalent ions (niobium, antimony and tantalum)[3,4] were prepared by electrospinning leading to a fibre-in-tube morphology. The doping led to increase of the intrinsically low electrical conductivity of the semiconductor oxide. The electrochemical stability of the different supports was evaluated in acidic medium at low and high potentials, coupling electrochemistry and spectroscopic methods.[5] IrO2 nanoparticles synthesized by a microwave-assisted polyol method were deposited onto the doped SnO2 nanomaterials. Their electrochemical activity towards the oxygen evolution reaction (OER) as well as their durability upon accelerated stress tests were evaluated.In order to enhance the PEMWE performance, the use of thin membranes reducing resistive effects is crucial. To avoid premature failure and gas permeability issues, reinforcing polymer nanofibrous webs were introduced in the PFSA matrix.[6] The nanocomposite membranes obtained led to greater mechanical robustness and reduced gas crossover while keeping high proton conductivity. [7]The nanocomposite electrocatalysts and membranes were used to prepare membrane-electrode assemblies and characterised in a PEMWE cell. Their performance and stability were investigated in different operating conditions and will be discussed. Daiane Ferreira da Silva, C.; Claudel, F.; Martin, V.; Chattot, R.; Abbou, S.; Kumar, K.; Jiménez-Morales, I.; Cavaliere, S.; Jones, D.; Rozière, J.; et al. Oxygen Evolution Reaction Activity and Stability Benchmarks for Supported and Unsupported IrO x Electrocatalysts. ACS Catal. 2021, 11, 4107–4116.Du, L.; Shao, Y.; Sun, J.; Yin, G.; Liu, J.; Wang, Y. Advanced catalyst supports for PEM fuel cell cathodes. Nano Energy 2016, 29, 314–322.Cavaliere, S.; Jiménez-Morales, I.; Ercolano, G.; Savych, I.; Jones, D.; Rozière, J. Highly Stable PEMFC Electrodes Based on Electrospun Antimony-Doped SnO2. ChemElectroChem 2015, 2, 1966–1973.Jiménez-Morales, I.; Haidar, F.; Cavaliere, S.; Jones, D.; Rozière, J. Strong Interaction between Platinum Nanoparticles and Tantalum-Doped Tin Oxide Nanofibers and Its Activation and Stabilization Effects for Oxygen Reduction Reaction. ACS Catal. 2020, 10, 10399–10411.Jiménez-Morales, I.; Cavaliere, S.; Dupont, M.; Jones, D.; Rozière, J. On the stability of antimony doped tin oxide supports in proton exchange membrane fuel cell and water electrolysers. Sustain. Energy Fuels 2019, 3, 1526–1535.Sood, R.; Cavaliere, S.; Jones, D.J.; Rozière, J. Nano Energy Electrospun nano fi bre composite polymer electrolyte fuel cell and electrolysis membranes. Nano Energy 2016, 26, 729–745.Sood, R.; Giancola, S.; Donnadio, A.; Zatoń, M.; Donzel, N.; Rozière, J.; Jones, D.J.; Cavaliere, S. Active electrospun nanofibers as an effective reinforcement for highly conducting and durable proton exchange membranes. J. Memb. Sci. 2021, 622.

Fabrication of perovskite solar cells with PCE of 21.84% in open air by bottom-up defect passivation and stress releasement

The archetypical n-type semiconductor material, tin oxide (SnO2), is common and well-known electron transport layer (ETL) material in regular perovskite solar cells (PSCs) due to the superior electron mobility and suitable energy level alignment with perovskite. However, plentiful detrimental defects concentrated at perovskite/SnO2 ETLs interface and unfavorable residual stress within perovskite films, compromise and dampen the photovoltaic performance and shelf stability of PSCs. Herein, alkali metal salts (i.e., 2, 2′-biquinoline-4, 4′-dicarboxylic acid alkali metal salts (BCA-2H, BCA-2Na, and BCA-2K)) are employed as pre-buried modifiers in SnO2 films to achieve a holistic amelioration of ETLs, perovskite photoactive layer, and their interface heterojunction. The BCA modification facilitates crystal orientation and crystalline of SnO2 nanocrystals, instrumental in decreasing trap state densities within functional layers, releasing interfacial residual tensile strain, and upgrading perovskite film performance. In comparison to BCA-2H- and BCA-2Na-doped ETLs, the BCA-2K decoration corroborate better defect passivation and stress release effect originating from preferable interface enhancement and desirable surface chemical properties. Consequently, the PSCs based on SnO2-BCA-2K ETL fabricated under open-air conditions deliver the champion efficiency of 21.84% accompanied by negligible hysteresis. Moreover, the unpacked devices maintain 81.2% of its original value after 1200 h storage under an ambient condition of 55 ± 5% (relative humidity, RH) and 25 ± 5 ℃ with open-circuit conditions.

Transparent radar-infrared stealth based on multilayer metamaterial structures

A flexible transparent composite metamaterial structure compatible with microwave absorption in the radar band and low emissivity in the infrared is proposed. The radar wave absorber and infrared shield layers, which can control microwave absorption and infrared emission respectively, are designed and fabricated on a transparent substrate using indium tin oxide material. It achieves 90% absorption over a wide frequency range of 2.12–15.87 GHz, wide incidence angle stability over a range of 50° and maintains absorption of more than 90% over a polarisation range of 70°. The emissivity of the metamaterial structure in the infrared band is approximately 0.25. The current distribution of the structure is analysed and the equivalent circuit model is developed to reveal the absorption mechanism. The test results are in general agreement with the simulation results, and the design has application value for multi-spectral stealth and transparent electromagnetic shielding.

Mn3O4@ZnO Hybrid Material: An Excellent Photocatalyst for the Degradation of Synthetic Dyes including Methylene Blue, Methyl Orange and Malachite Green

In this study, we synthesized hybrid systems based on manganese oxide@zinc oxide (Mn3O4@ZnO), using sol gel and hydrothermal methods. The hybrid materials exhibited hierarchical morphologies and structures characterized by the hexagonal phase of ZnO and the tetragonal phase of Mn3O4. The hybrid materials were tested for degradation of methylene blue (MB), methyl orange (MO), and malachite green (MG) under ultraviolet (UV) light illumination. The aim of this work was to observe the effect of various amounts of Mn3O4 in enhancing the photocatalytic properties of ZnO-based hybrid structures towards the degradation of MB, MO and MG. The ZnO photocatalyst showed better performance with an increasing amount of Mn3O4, and the degradation efficiency for the hybrid material containing the maximum amount of Mn3O4 was found to be 94.59%, 89.99%, and 97.40% for MB, MO and MG, respectively. The improvement in the performance of hybrid materials can be attributed to the high charge separation rate of electron-hole pairs, the co-catalytic role, the large number of catalytic sites, and the synergy for the production of high quantities of oxidizing radicals. The performance obtained from the various Mn3O4@ZnO hybrid materials suggest that Mn3O4 can be considered an effective co-catalyst for a wide range of photocatalytic materials such as titanium dioxide, tin oxide, and carbon-based materials, in developing practical hybrid photocatalysts for the degradation of dyes and for wastewater treatment.

Design of ultrathin transparent cross‐polarization converter

AbstractIn this letter, we propose a novel transparent wideband reflective metasurface based on indium tin oxide (ITO) material. The unit consists of four C‐shaped structures of different sizes. ITO material was plated on the surface of soda‐calcium glass by magnetron sputtering. Floquet port and master‐slave boundary conditions were set up in ANSYS HFSS for simulation. Simulation results show that the polarization conversion ratio reaches 90% in the range of 10.9–20.5 GHz, with little change in the 30° incident angle range. Experimental results are consistent with the simulation ones. The proposed transparent cross‐polarization converter may be used in the devices integrated with solar cells.

Efficient Near-Infrared PbS Quantum Dot Solar Cells Employing Hydrogenated In2 O3 Transparent Electrode.

Infrared solar cells are regarded as candidates for expanding the solar spectrum of c-Si cells, and the window electrodes are usually transparent conductive oxide (TCO) such as widely used indium tin oxide material. However, due to the low transmittance of the TCO in the near-infrared region, most near-infrared light cannot penetrate the electrode and be absorbed by the active layer. Here, the propose a simple procedure to fabricate the window materials with high near-infrared transmittance and high electrical conductivity, namely the hydrogen-doped indium oxide (IHO) films prepared by room temperature magnetron sputtering. The low-temperature annealed IHO conductive electrodes exhibit high mobility of 98 cm2 V-1 s-1 and high infrared transmittance of 85.2% at 1300nm, which endows thelead quantum dot infrared solar cell with an improved short-circuit current density of 37.2mA cm-2 and external quantum efficiency of 70.22% at 1280nm. The proposed preparation process is simple and compatible with existing production lines, which gifts the IHO transparent conductive film great potential in broad applications that simultaneously require high infrared transmittance and high conductivity.

MEMS cantilever–controlled plasmonic colors for sustainable optical displays

Conventional optical displays using indium tin oxide and liquid crystal materials present challenges for long-term sustainability. We show here a cost-effective and complementary metal-oxide semiconductor (CMOS)–compatible fast and full-range electrically controlled RGB color display. This is achieved by combining transmission-based plasmonic metasurfaces with MEMS (microelectromechanical systems) technology, using only two common materials: aluminum and silicon oxide. White light is filtered into RGB components by plasmonic metasurfaces made of aluminum nanohole arrays. The transmission through each color filter is modulated by MEMS miniaturized cantilevers fabricated with aluminum and silicon oxide on top of the color filters. We show that the relative transmission of a color subpixel can be freely modulated from 35 to 100%. The pixels can also operate well above 800 Hz for future ultrafast displays. Our work provides a road to future circular economic goals by exploiting advances in structural colors and MEMS technologies to innovate optical displays.

An Optically Transparent Metantenna for RF Wireless Energy Harvesting

We propose a novel transparent metasurface antenna (metantenna) based on indium tin oxide (ITO) material for simultaneously achieving wireless energy harvesting (WEH) at radio frequency (RF) bands and efficient transmission of visible light. We adopt the design method of aperture-coupled metantenna to realize broadband and low-profile RF WEH. Then, we replace the conventional opaque metal material with an ITO coating with a sheet impedance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1~\Omega $ </tex-math></inline-formula> /sq to achieve the transparency of the proposed design. In order to obtain the balance between electrical performance and optical transmittivity (OT), we modify the metasurface structure to further improve the OT of the metantenna. The fabricated transparent metantenna shows an OT of more than 50%. A measured impedance bandwidth of 43.6% from 1.40 to 2.18 GHz is obtained to cover 2G and 3G wireless communication bands. Through designing the broadband rectifying circuit and the energy management circuit, we can obtain the maximum RF-dc efficiency of 65% and a stable dc output voltage of 3.4V, while the overall RF energy harvesting efficiency could reach 14.5% with the power input of 0 dBm. In addition, through the solar energy harvesting test, we can demonstrate the potential of the proposed design to work with solar panels for realizing efficient RF/solar hybrid energy harvesting.

Metal-Free Transparent Three-Dimensional Flexible Electronics by Selective Molecular Bridges.

Flexible and transparent electronics is a new generation of device enabling modern interactive designs, which facilitates the recent development of low-cost, lightweight, and flexible materials. Although conventional indium tin oxide material still dominates the major market, its brittleness and steadily increasing price drive scientists to search for other alternatives. To meet the high demand, numerous metallic or organic conductive materials have been developed, but their poor adhesion toward supporting substrates and the subsequent circuit patterning approach remains problematic. In this study, a robust metal-free flexible conductive film fabrication strategy is introduced. The flexible polyethylene terephthalate (PET) film is utilized as the base, where a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conductive layer is tightly linked onto this supporting substrate. An interface activation process, i.e., oxygen plasma treatment, generates PET surface active spots to react with the subsequently introduced poly(vinyl alcohol) (PVA) molecule functional groups. This spatially selective PVA molecular bridge therefore acts as a dual-function intermediate layer through covalent bonding toward PET and hydrogen bonding toward PEDOT:PSS to conjugate two distinct materials. This PEDOT:PSS/PVA/PET film delivers superior physical properties, such as a high conductivity of 38.2 Ω/sq and great optical transmittance of 84.1%, which are well tunable under conductive polymer thickness controls. The film is also durable and can maintain original electrical properties even under serious bending for hundreds of cycles. Relying on these outstanding performances, arbitrary conductive circuits are built on this flexible substrate and can function as normal electronics when integrated with multiple electronic parts, e.g., light-emitting diodes (LEDs). Superior electrical signal outputs are achieved when complicated stereo structures including folding, splicing, interlacing, and braiding are incorporated, enabling the use of these films for flexible three-dimensional electronics assembling. Space identifying smart key and lock pair, origami rabbit-carrot touch response, pressure-stimulated jumping frog, and moving dinosaur recognition designs realize these PEDOT:PSS/PVA/PET film-based human-machine interactive devices. This flexible, transparent, and conductive film generation approach by molecular bridge creation should facilitate future development of flexible or foldable devices with complex circuits.

Study of new solar film based on near-infrared shielding

In areas with strong light, the appearance of solar greenhouse covering material effectively reduces the temperature in the greenhouse and improves the efficiency of solar energy utilization, but there are many shortcomings in the material structure of solar greenhouse covering materials, such as low visible light transmittance, low reflectance of near-infrared radiation, poor insulation and so on. Based on the above questions, a nano-scale material film consisting of the sloped arrangement of the indium tin oxide and metal material is proposed, a transfer matrix method is used to study its transmittance and reflectance under visible and near-infrared light. The study finds that the material and structure has more than 93% transmittance in visible light and the reflectance of the near-infrared band is more than 95%. Simulation results confirm the material's potential to become a new type of solar greenhouse film.