Amorphous Tin Research Articles

Investigating the Local Bonding Structure of Amorphous Zinc Tin Oxide to Elucidate the Effect of Altering the Intercation Ratio.

In this paper, the local bonding structure in amorphous zinc tin oxide (a-ZTO) is probed using a combination of XANES and EXAFS techniques at the Zn and Sn K-edges to gain insight into charge carrier generation in the material. a-ZTO is prepared using two growth methods; spray pyrolysis and magnetron sputtering. It is seen that a-ZTO grown by magnetron sputtering shows no changes in the chemical environment as the cation ratio is varied; meanwhile, XANES analysis of spray pyrolysis grown samples shows alterations to spectra likely due to the effects caused by different precursors. Although a slight shift in Sn-O bond length is visible between magnetron sputtered and spray grown samples, no correlation could be discerned between bond length and variation in cation ratio. It is concluded that a-ZTO, while amorphous over longer ranges, is locally composed of ZnO and SnO2 "building blocks". An alteration in the cation ratio changes the hybridization at the conduction band minimum, resulting in the observed variation in the mobility, charge carrier concentration, and bandgap.

Inelastic relaxation in tin oxide thin films with an amorphous structure

Inelastic relaxation in amorphous tin oxide thin films obtained by ion-beam sputtering in an argon atmosphere were studied. The films retain an amorphous structure after annealing at temperatures below 623 K for 30 min and crystallization begins after annealing at 673 K with the formation of two phases, where the SnO2 phase predominates over the SnO phase. Annealing at 723 K for 30 min leads to a partial transition of the SnO crystalline phase to the SnO2 phase.The temperature dependence of internal friction revealed maxima at 585 K and 603 K, identified as β - relaxation maxima, as well as at 690 K, identified as α - relaxation maximum. It is assumed that the β - relaxation maxima at 585 K and 603 K are associated with local hopps of oxygen atoms within the defect structure of SnO2 and with local hopps of tin atoms within the defect structure of SnO, respectively. The exponential increase in internal friction up to a temperature of 690 K in the α - relaxation region is associated with the diffusion of nonequilibrium vacancy-like defects of the amorphous structure below the glass transition temperature and equilibrium ones above the glass transition temperature. Estimates of the migration energy and formation energy of vacancy-like defects in amorphous tin oxide were made.

Amorphous Cobalt Tin Oxide/Reduced Graphene Oxide Decorated on Graphite Felt as Positive Electrode for Vanadium Redox Flow Battery

The Vanadium Redox Flow Battery (VRFB) stands out as one of the most promising large-scale energy storage systems. Nevertheless, the graphite electrode materials commonly used in VRFBs often exhibit drawbacks such as limited electrochemical activity and insufficient conductivity, ultimately resulting in suboptimal performance for the VRFB. In this study, we utilized highly conductive reduced graphene oxide (rGO) as a carrier for cobalt tin oxide (CoSnO3), aiming to enhance their catalytic capability towards vanadium ions. CoSnO3/rGO composite was confirmed using XRD and TEM, revealing nanoboxes morphology and amorphous structure. XPS and EPR analysis showed an increase in oxygen vacancies after composite formation. In order to further prove the effect of CoSnO3/rGO composite catalyst modified graphite felt, the modified graphite felt electrode was applied to the positive electrodes of VRFB, and the charge and discharge tests at different current densities were carried out. At a current density of 160 mA/cm², the composite demonstrated a voltage efficiency of 74.22%, surpassing the heat treated graphite felt by 2.69%. Noteworthy enhancements in capacitance were also evident at this specific current density. Furthermore, stability testing over 50 cycles revealed no significant degradation, underscoring the superior performance and outstanding durability of the CoSnO3-rGO modified graphite felt throughout charge and discharge cycling. The result of this study highlight the promising potential of CoSnO3-rGO composites as efficient catalysts for vanadium redox flow batteries, providing improvements in electrochemical performance and long-term stability.

Polyaniline-modified amorphous tin-based Prussian blue analogue as cathodes for long-life aqueous zinc ion batteries

Prussian blue analogs (PBAs) have emerged in the field of aqueous zinc ion batteries (AZIBs) owing to their simple synthesis method and three-dimensional open framework structure. Although PBAs have high redox potentials, the unsatisfactory specific capacity and poor electrical conductivity limit their development to some extent. In this work, amorphous tin hexacyanoferrate (SnHCF) and polyaniline (PANI) were combined to form SnHCF/PANI composite. The synergistic effect of the amorphous structure of SnHCF and PANI with good conductivity makes the SnHCF/PANI electrode exhibit excellent redox activity and achieve rapid ion/electron transfer. When used as a cathode in AZIBs, the SnHCF/PANI provides a high specific capacity (136.8 mAh g−1 at 0.5 A g−1) and excellent cycling stability (a discharge specific capacity of 54.3 mAh g−1 after 2500 cycles at 2 A g−1). This work offers a new idea for the development of PBAs-based composites as cathode materials for AZIBs.

In situ one step growth of amorphous tin oxide electron transport layer for high-performance perovskite solar cells.

Tin oxide used in electron transport layer (ETL) exhibits key role in transmitting electrons and blocking holes in perovskite solar cells (PSCs) device. However, crystal tin oxide nanoparticles (NPs) become necessary to form SnO2 film by method of spin-coating, resulting in possible surface defect and cracks among SnO2 NPs, corresponding to unsatisfied performance PSCs. Herein, an amorphous tin oxide thin film is creatively in situ grew onto Fluorine-doped Tin Oxide (FTO) substrate as ETL. The designed solar cell device with structure of FTO/SnO2/MAPbI3/Sprio-OMeTAD/Ag owns a champion photoelectric conversion efficiency (PCE) up to 17.64%, 76.20% of filling coefficient (FF), and 1.09 V of open-circuit voltage (Voc), in comparing with 16.43%, 64.35% and 1.05 V for control group (crystal tin oxide as ETL), respectively. Besides, the champion device keeps 83.33% of initial PCE under nitrogen (N2) condition for one month, in comparison with 76.09% for control group. This work provides a viable strategy for facile preparing amorphous tin oxide film based ETL in perovskite solar cells.

Nanoscale-doped dual-channel for improved performance and reliability of Hf: IGTO / a-IGTO thin film transistor

Amorphous oxide semiconductors are widely used in the backplane thin film transistors (TFTs) of displays and are extensively researched as materials for next-generation memory devices. However, they face reliability degradation due to stress factors such as thermal, bias, and light exposure. To mitigate these issues, extensive research is focused on improvements, including doping, enhancing crystallinity, and applying pre-and post-treatments. This study investigates the significantly improved reliability and electrical properties of amorphous indium gallium tin oxide (a-IGTO) TFTs by adopting a dual-channel configuration through simultaneous co-sputtering of HfO2 and IGTO targets. The device fabrication involved co-sputtering HfO2 and IGTO at the gate oxide interface, followed by depositing an IGTO-only layer, rather than doping the entire channel material. The effect of varying Hf concentration was evaluated by applying different HfO2 sputtering powers. Optimal hafnium doping reduced the threshold voltage of the a-IGTO TFT from −0.85V to 0.15V compared to the pristine a-IGTO TFT, while enhancing the field-effect mobility (μFE). Furthermore, the Hf-doped device exhibited improved stability, with a reduced threshold voltage shift (ΔVth) under positive (+15 V) and negative(-15 V) bias stress at 3000s, decreasing from 11.5 V to 4.8 V, and 4.7 V–1.1 V, respectively. This study proposes a novel device fabrication method to enhance the reliability of amorphous oxide semiconductor, addressing their inherent stress-related issues.

Light Effect on Amorphous Tin Oxide Thin‐Film Transistors

Amorphous tin oxide (a‐SnOx) is a potential transparent oxide semiconductor candidate for future large‐area electronic applications. The thin‐film transistor (TFT) mobilities reach ≈100 cm2 Vs−1, a mobility higher than other multiple cation‐based oxide semiconductor TFTs. Few optical properties have been reported so far and therefore both the effect of visible light and negative bias illumination stress (NBIS) on a‐SnOx TFT performances, known to dramatically impact oxide semiconductor‐based TFTs, have been investigated. The variation of density of states (DOS) due to NBIS by device simulation is analyzed, and a fourfold increase of the donor‐like states and a decrease in the band edge DOS from 2.3 to 2.0 × 1019 cm−3 eV−1 are showed. The evaluation of the effect of neutral, singly, and doubly ionized oxygen vacancies by density functional theory using 95 atoms reveals not only states in the gap of SnO2, but also variations in the electron density, and modifications in the crystal parameters compared to a structure without an oxygen vacancy. Material and device simulation analysis reveal that the oxygen vacancies have a dramatical impact on the DOS in the gap of SnO2 and can explain the NBIS phenomenon observed in a‐SnOx TFT.

Enhanced electrical properties of amorphous In-Sn-Zn oxides through heterostructuring with Bi2Se3 topological insulators

Amorphous indium tin zinc oxide (a-ITZO)/Bi2Se3 nanoplatelets (NPs) were fabricated using a two-step procedure. First, Bi2Se3 NPs were synthesized through thermal chemical vapor deposition at 600 °C on a glass substrate, and then a-ITZO was deposited on the surface of the Bi2Se3 NPs via magnetron sputtering at room-temperature. The crystal structures of the a-ITZO/Bi2Se3 NPs were determined via X-ray diffraction spectroscopy and high-resolution transmission electron microscopy. The elemental vibration modes and binding energies were measured using Raman spectroscopy and X-ray photoelectron spectroscopy. The morphologies were examined using field-emission scanning electron microscopy. The electrical properties of the a-ITZO/Bi2Se3 NPs were evaluated using Hall effect measurements. The bulk carrier concentration of a-ITZO was not affected by the heterostructure with Bi2Se3. In the case of the Bi2Se3 heterostructure, the carrier mobility and conductivity of a-ITZO were increased by 263.6% and 281.4%, respectively, whereas the resistivity of a-ITZO was reduced by 73.57%. This indicates that Bi2Se3 significantly improves the electrical properties of a-ITZO through its heterostructure, expanding its potential applications in electronic and thermoelectric devices.

Fretting wear resistance of amorphous/amorphous (AlCrFeNi)N/TiN high entropy nitride nanolaminates

The application of amorphous high entropy ceramics as wear-resistant materials is limited due to their inherent brittleness at room temperature and strain softening during deformation. In order to overcome this limitation, we constructed amorphous/amorphous (AlCrFeNi)N/TiN nanolaminates with varying modulation period thickness by introducing a second amorphous phase through reactive radio frequency (RF) magnetron sputtering, along with corresponding monolithic amorphous films. Microstructure, mechanical properties, and tribological behaviors of the films were characterized wear in detail. Fretting wear results show that the nanolaminates with an average modulation period of 6 nm exhibited a wear rate of 2.8 times lower than that of the (AlCrFeNi)N film and 8.4 times lower than that of the TiN film. Further analysis using FIB-TEM revealed that the enhanced wear resistance of (AlCrFeNi)N/TiN nanolaminates was attributed to the high-density heterointerfaces. These interfaces inhibited the initiation and propagation of mature shear bands and acted as barriers to stress distribution. Additionally, the oxide composite layer at the interface demonstrated a synergistic effect through a mechanically induced tribo-chemical reaction, resulting in slight plastic deformation. For the amorphous (AlCrFeNi)N film, moderate wear resistance was achieved through the formation of transfer layer at the interface. For the amorphous TiN film, the dimensional stability of the film deteriorates due to the significant strain softening that occurs during deformation. This study deepens our understanding of the friction mechanisms involved in amorphous high entropy ceramics, offering valuable insights for the design of high damage-resistant materials.

Chitosan-photocatalyst nanocomposite on polyethylene films as antimicrobial coating for food packaging

Chitosan (CS), an edible and non-toxic natural biopolymer, has been widely used in food preservation attributed to its intrinsic antimicrobial, biodegradable, and excellent film-forming properties. In this work, we report photocatalyst-loaded chitosan coating on commercial polyethylene (PE) film with enhanced antimicrobial properties for food packaging application. To improve the chemical stability of zinc oxide (ZnO) photocatalyst in acidic chitosan matrix, a thin layer (1–5 nm) of amorphous tin oxide (SnOx) was coated on ZnO nanoparticles. Consequently, the charge transfer efficiency of ZnO is improved and most of the surface defects are retained according to the studies of UV–Vis and fluorescence spectroscopy. The thin SnOx coating on ZnO was observed by high-resolution transmission electron microscopy (HRTEM) and its effects on crystallinity and particle size of ZnO were examined using X-ray diffraction (XRD) and particle sizer, respectively. The addition of ZnO@SnOx particles in chitosan coating increases water contact angle (WCA) and enhances thermal stability of chitosan coating. The antimicrobial activity of chitosan, ZnO-SnOx nanoparticles, and CS-ZnO@SnOx coated PE films were examined against both Gram-negative (E. coli, A. faecalis) and Gram-positive (S. aureus, B. subtilis) bacteria. Compared to the limited antimicrobial effects of chitosan, ZnO-SnOx demonstrates an improved inhibition effect on bacterial growth over 48 h period under light. For the CS-ZnO@SnOx nanocomposite coated PE films, no inhibition zone was observed due to the limitation of disc diffusion method. Meanwhile, there were no bacterial colonies found to develop on the film, rendering this CS nanocomposite coating a good candidate for food packaging applications.

Resistive switching and battery-like characteristics in highly transparent Ta2O5/ITO thin-films

Highly transparent resistive-switching (RS) devices were fabricated by growing amorphous tantalum pentoxide (a-Ta2O5) and indium tin oxide (a-ITO) thin films on barium-borosilicate glass (7059) substrates, using electron beam evaporation. These layers exhibited the transmittance greater than ~ 85% in the full visible region and showed RS behavior and battery-like IV characteristics. The overall characteristics of RS can be tuned using the top electrode and the thickness of a-Ta2O5. Thinner films showed a conventional RS behavior, while thicker films with metal electrodes showed a battery-like characteristic, which could be explained by additional redox reactions and non-Faradaic capacitive effects. Devices having battery-like IV characteristics showed higher enhanced, retention and low-operation current.

First Experimental Evidence of Amorphous Tin Oxide Formation in Lead‐Free Perovskites by Spectroscopic Ellipsometry

The most promising lead‐free options for producing perovskite solar cells are tin halide perovskite materials. Herein, while in situ monitoring the optical evolution of the material in humid air, spectroscopic ellipsometry is used to investigate the dielectric function of FASnI3 layers (with and without additives) within the range of 1–5 eV. According to calculations based on the density functional theory that shows oxygen diffusion on FASnI3 surfaces, the steady decrease in absorption coefficient in the band gap region (1.47 eV) and simultaneous increase in absorption in the 3–4.5 eV region suggest the production of amorphous tin oxide. Concurrently, X‐ray diffraction reveals a clear degradation of FASnI3. With the addition of sodium borohydride and dipropylammonium iodide, the optically active area of about 1.47 eV is preserved for a longer period while SnO2 production is prevented. Last but not least, FASnI3's stability is investigated in dry N2 environment and shown that it is optically durable for thermal operations up to 100 °C, particularly when additives are used.

Preparation of large-scale uniformly crystallized ITO thin films by rapid infrared annealing technique

This paper proposes three engineering application technology applications for rapid infrared annealing (RIA): scanning annealing, lamp array preheating and scanning annealing, and lamp array annealing. For the dynamic scanning annealing method, the influence of the working distance from the infrared lamp to the amorphous indium tin oxide (ITO) film and the scanning speed on the heating of the film surface were studied. For lamp array preheating and scanning annealing, the attenuation of the compressive stress on the surface of the chemically strengthened glass under the condition of low temperature and the long holding time were revealed. For lamp array annealing, the influence of this technology on the optical and electrical properties of the ITO film and the surface compressive stress of chemically strengthened glass were studied. Using the lamp array preheating and scanning annealing and lamp array annealing technology, not only a crystalline ITO film with excellent optical and electrical properties and uniformity can be prepared quickly, but also the impact of the crystallization process on chemically strengthened glass can be reduced greatly.

Different Crystallization Behavior of Amorphous ITO Film by Rapid Infrared Annealing and Conventional Furnace Annealing Technology.

An amorphous indium tin oxide (ITO) film (Ar/O2 = 80:0.5) was heated to 400 °C and maintained for 1-9 min using rapid infrared annealing (RIA) technology and conventional furnace annealing (CFA) technology. The effect of holding time on the structure, optical and electrical properties, and crystallization kinetics of ITO films, and on the mechanical properties of the chemically strengthened glass substrates, were revealed. The results show that the nucleation rate of ITO films produced by RIA is higher and the grain size is smaller than for CFA. When the RIA holding time exceeds 5 min, the sheet resistance of the ITO film is basically stable (8.75 Ω/sq). The effect of holding time on the mechanical properties of chemically strengthened glass substrates annealed using RIA technology is less than that of CFA technology. The percentage of compressive-stress decline of the strengthened glass after annealing using RIA technology is only 12-15% of that using CFA technology. For improving the optical and electrical properties of the amorphous ITO thin films, and the mechanical properties of the chemically strengthened glass substrates, RIA technology is more efficient than CFA technology.

Serially connected tantalum and amorphous indium tin oxide for sensing the temperature increase in IGZO thin-film transistor backplanes

A temperature sensor embedded in an In-Ga-Zn oxide (IGZO) TFT was evaluated after fabrication to facilitate monitoring of the temperature distribution on a thin-film transistor (TFT) array. Because the proposed temperature sensor uses the same material as the TFT, no additional process or material is required. Moreover, it can be used as a light shield layer because the temperature sensor is located on a TFT. The temperature sensor used in this study was serially connected to indium tin oxide and a metal. As the temperature increased to 120 °C, the output voltage of the temperature sensor increased to 176.6 mV. The sensitivity, hysteresis, and repeatability were 0.85 mV/°C, 3.56 %, and 0.04 %, respectively. The temperature sensor was integrated into an amorphous IGZO bottom-gate TFT. The TFT exhibited a field-effect mobility of 8.2 cm2V−1·s−1 and threshold voltage of 5.2 V. As the drain current increased from 300 µA to 1.1 mA, the temperature increased from 26 to 32.9 °C, and the output voltages of the temperature sensor augmented from 66 to 76 mV. The integrated temperature sensors enable us to measure the temperature distribution in a display panel and compensate for image deterioration due to increased temperature.

Illuminating Trap Density Trends in Amorphous Oxide Semiconductors with Ultrabroadband Photoconduction

AbstractUnder varying growth and device processing conditions, ultrabroadband photoconduction (UBPC) reveals strongly evolving trends in the defect density of states (DoS) for amorphous oxide semiconductor thin‐film transistors (TFTs). Spanning the wide bandgap of amorphous InGaZnOx (a‐IGZO), UBPC identifies seven oxygen deep donor vacancy peaks that are independently confirmed by energetically matching to photoluminescence emission peaks. The subgap DoS from 15 different types of a‐IGZO TFTs all yield similar DoS, except only back‐channel etch TFTs can have a deep acceptor peak seen at 2.2 eV below the conduction band mobility edge. This deep acceptor is likely a zinc vacancy, evidenced by trap density which becomes 5‐6× larger when TFT wet‐etch methods are employed. Certain DoS peaks are strongly enhanced for TFTs with active channel processing damage caused from plasma exposure. While Ar implantation and He plasma processing damage are similar, Ar plasma yields more disorder showing a ≈2 × larger valence‐band Urbach energy, and two orders of magnitude increase in the deep oxygen vacancy trap density. Changing the growth conditions of a‐IGZO also impacts the DoS, with zinc‐rich TFTs showing much poorer electrical performance compared to 1:1:1 molar ratio a‐IGZO TFTs owing to the former having a ∼10 × larger oxygen vacancy trap density. Finally, hydrogen is found to behave as a donor in amorphous indium tin gallium zinc oxide TFTs.

Defect-rich ultrafine amorphous tin oxyhydroxide nanoparticle anode for high-performance lithium-ion batteries

Metal oxyhydroxide nanostructures are attractive anode materials for lithium-ion batteries (LIBs) because of their appreciable theoretical capacity. In their amorphous phase they can greatly relieve volume changes during cycling, enhancing cycle stability. Here, we successfully produce amorphous tin oxyhydroxide nanoparticles (a-SnOOH NPs) with sizes of less than 5 nm using a facile electrochemical anodization method. Plentiful oxygen vacancies (VOs) are generated in the NPs by simply introducing glycerol into the electrolyte. The numerous defects further facilitate the electrochemical kinetics of the a-SnOOH NPs with rich VOs (a-SnOOH/VO NPs), resulting in better cell performance. With the synergetic combination of amorphous nature and abundant defect sites, the a-SnOOH/VO NP anode for LIBs exhibits a considerable initial discharge capacity of 2171.3 mAh/g at a current rate of 0.2 C and retains a high reversible capacity with a coulombic efficiency of 98.4% after 300 cycles. The ultrafine particles also deliver exceptional rate capability with a large capacity of 641.9 mAh/g even at a high current rate of 20 C.

Sorption and separation studies of Nd(III) and Dy(III) using amorphous tin(IV) phosphate

Sorption and separation studies of Nd(III) and Dy(III) using amorphous tin(IV) phosphate

High-Performance Amorphous InGaSnO Thin-Film Transistor with ZrAlOx Gate Insulator by Spray Pyrolysis

Here, we report the high-performance amorphous gallium indium tin oxide (a-IGTO) thin-film transistor (TFT) with zirconium aluminum oxide (ZAO) gate insulator by spray pyrolysis. The Ga ratio in the IGTO precursor solution varied up to 20%. The spray pyrolyzed a-IGTO with a high-k ZAO gate insulator (GI) exhibits the field-effect mobility (μFE) of 16 cm2V−1s−1, threshold voltage (VTH) of −0.45 V subthreshold swing (SS) of 133 mV/dec., and ON/OFF current ratio of ~108. The optimal a-IGTO TFT shows excellent stability under positive-bias-temperature stress (PBTS) with a small ΔVTH shift of 0.35 V. The enhancements are due to the high film quality and fewer interfacial traps at the a-IGTO/ZAO interface. Therefore, the spray pyrolyzed a-IGTO TFT can be a promising candidate for flexible TFT in the next-generation display.

An effective solution to optimize the saddle-shape warpage in 3D IC applications by patterning laser treatment

The asymmetric saddle-shape warpage is one of the hardest limitations on the development of three-dimensional integrated circuits (3D ICs) as the vertical integration increases. To improve the product yield, an effective method for saddle-shape warpage reduction in 3D IC production by backside patterning laser annealing treatment with a multilayer structure is investigated in this work. The reduction of saddle-shaped warpage by patterning laser treatment is the first time in 3D NAND array wafer application and through simulations and experiments, the laser annealing pattern is determined. In addition, the materials of the multilayer structure are selected as amorphous Al2O3 and TiN according to experiments and theoretical analysis. As a result, a conformal 47.8 µm optimization of the saddle-shape warpage is successfully reached in a control wafer test by patterning laser annealing treatment.