Indium Zinc Tin Oxide Research Articles

Amorphous InZnSnO thin-film-transistors performance enhancement with low-energy Xenon Pulsed-light annealing

The electrical characteristics and stability of amorphous indium-zinc-tin oxide (IZTO) thin-film transistors (TFTs) were significantly improved in this study using low-energy Xenon pulsed-light annealing (PLA). In comparison to conventional furnace annealing (FA), PLA treatment significantly reduced the processing temperature and annealing time. Besides, the defect states are obviously reduced from 1.73×1012 cm-2 to 6.53×1011 cm-2 by PLA treatment, resulting in improved device electrical characteristics and enhanced reliability, including improved carrier mobility from 20.08 to 39.61 cm2/V∙s, threshold voltage from 0.82 to 0.24 V, subthreshold swing (S.S.) from 0.54 to 0.24 V/decade, and the ON/OFF current ratio from 2.32×107 to 7.31×108. In addition, the enhanced stability is observed under both positive gate-bias stress (PGBS) of VGS = 30 V and negative gate-bias stress (NGBS) of VGS = –30 V for a stress duration of 3000 s. The threshold voltage shift (ΔVTH) is reduced from 8.31 V to 1.65 V and from –3.93 V to –1.51 V, respectively. This is the first time low-energy PLA was conducted for IZTO TFT performance improvement.

Numerical simulation of lead-free MASnI3 perovskite/silicon heterojunction for solar cells and photodetectors

Lead free n-type doped methyl ammonium tin iodide (MASnI3) perovskite/p-Silicon heterojunction (HJ) for solar cells and photodetectors are simulated using AFORS-HET automat simulation software. In the earlier work, lead based methyl ammonium lead iodide perovskite/silicon (n-MAPbI3/p-Si) heterojunction devices were studied. In view of the toxicity and environmental concerns related to lead, it is substituted with tin to make lead-free tin based perovskite to make n-MASnI3/p-Si HJ devices. Various parameters associated with the layers of MASnI3 perovskite and silicon wafer like, Band gap, thickness, doping concentration and texturing angle have been optimized. Various transparent conducting oxide (TCO) materials like indium tin oxide (ITO) and zinc oxide (ZnO) are used and its performance with ideal device is compared. Various metals are considered as front and back contact, to obtain best metals for each sides. This study investigates the potential of lead-free perovskite materials in solar cells, achieving a notable efficiency improvement compared to traditional lead-based counterparts. Our numerical simulations demonstrate that the optimized lead-free perovskite with structures, n-MASnI3/p-Si heterojunction can reach efficiencies of 27.2%. These findings suggest that lead-free perovskites could serve as a viable, environmentally friendly alternative in the photovoltaic industry.

Highly Scaled BEOL-Compatible Thin Film Transistors With Ultrathin Atomic Layer Deposited Indium–Tin–Zinc–Oxide Channel

Highly Scaled BEOL-Compatible Thin Film Transistors With Ultrathin Atomic Layer Deposited Indium–Tin–Zinc–Oxide Channel

Evaluation of Aging Effects of Zinc Oxide on the Optical Properties of Porous Silicon-Zinc Oxide Heterojunction Photodetector Device

Porous silicon is very important for integrated technology because of its many superior properties, such as suitability for mass production, easy and controlled production, and adjustable electrical and optical properties. Semiconductors with metal oxides, such as indium oxide, indium tin oxide, tin oxide, and zinc oxide, are highly preferred in optical devices. Among these metal oxides, zinc oxide is preferred for photodetectors because of its stable crystal structure and large exciton binding energy of 60 meV. Researchers have conducted studies on photodetectors with porous silicon-zinc oxide heterojunction structures. The importance of the stable operation of devices has been emphasized. Therefore, in this study, a porous silicon-based zinc oxide heterojunction structure suitable for photodetector production was formed, and the effect of aging on zinc oxide was investigated over time. As a result of the investigation, it was observed that the intensity decreased approximately 2.5 times at the end of 365 days owing to the aging of zinc oxide. In addition, UV spectroscopy measurements were performed to investigate the optical properties that affect their operation as photodetectors. Because the PS-ZnO heterojunction functions as a detector in the UV region, the absorption and reflectivity of the PS-ZnO heterojunction were investigated, especially in the UV region. From the measurements, it was observed that aging decreased absorption and increased reflectance. These findings underscore the negative impact of aging on photodetector performance.

Encapsulation of flexible transparent electrodes based on indium zinc tin oxide with highly transparent and mechanically robust polymer dielectrics

This study was aimed at comprehensively investigating the utility of polymethyl methacrylate (PMMA) and CYTOP as encapsulation layers for flexible transparent electrodes composed of indium zinc tin oxide (IZTO). Optical modeling and experimental techniques were combined to assess the viability of PMMA and CYTOP as encapsulation materials. Optical modeling suggested that PMMA and CYTOP are well-suited for IZTO encapsulation. Subsequent experiment confirmed that the transmittance values of IZTO-films remained unaffected when encapsulated with PMMA and CYTOP. To examine the influence of encapsulation on mechanical resilience, all film, including untreated IZTO and IZTO treated with PMMA/CYTOP, were subjected to 20,000 bending cycles. The mechanical stability and optical properties of the IZTO film were considerably enhanced when encapsulated with these insulating materials. The improvement in transmittance was attributable to the lower refractive index of PMMA and CYTOP. Furthermore, scanning electron microscopy images demonstrated that the remarkable flexibility of PMMA and CYTOP effectively prevented the formation of cracks on the IZTO film, underscoring their pivotal role in enhancing the mechanical robustness of IZTO. In summary, this research highlights the potential of PMMA and CYTOP as efficient encapsulation materials for IZTO-based flexible transparent electrodes, offering dual benefits in terms of optical performance and mechanical durability.

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.

Inkjet printing high mobility indium-zinc-tin oxide thin film transistor

Metal oxide thin film transistor has been widely used in flat panel display industry because of its low leakage current, high mobility and large area uniformity. Besides, with the development of printed display technology, inkjet printing process can fabricate the customizable patterns on diverse substrates with no need of vacuum or lithography to be used, thus significantly reducing cost and receiving more and more attention. In this paper, we use inkjet printing technology to prepare a bottom gate bottom contact thin film transistor (TFT) by using indium-zinc-tin-oxide (IZTO) semiconductor. The surface morphology of the printed IZTO film is modified by adjusting the solvent composition and solute concentration of the printing precursor ink. The experimental result show that the use of binary solvents can effectively overcome the coffee ring shape caused by the accumulation of solute edge in the volatilization process of a single solvent, ultimately presenting a uniform and flat contour surface. Further increase in solute concentration is in favor of formation of convex surface topology. The reason for the formation of the flat surface of the oxide film is the balance between the inward Marangoni reflux of the solute and the outward capillary flow during volatilization. In addition, IZTO thin film transistor printed with binary solvents exhibits excellent electrical properties. The ratio of width/length = 50/30 exhibits a high on-off ratio of 1.21×10<sup>9</sup>, a high saturation field-effect mobility is 16.6 cm<sup>2</sup>/(V·s), a low threshold voltage is 0.84 V, and subthreshold swing is 0.24 V/dec. The uniform and flat active layer thin film pattern can form good contact with the source leakage electrode, and the contact resistances of TFT devices with different width-to-length ratios are less than 1000 Ω, which can reach the basic conditions of high mobility thin film transistors prepared by inkjet printing. Therefore, using solvent mixture provides a universal and simple way to print oxide films with required surface topology, and present a visible path for inkjet printing of high-mobility thin film transistors.

Spinel Single Phase Indium Zinc Tin Oxide Thin-Film Transistors with High Mobility and Excellent Uniformity

Spinel Single Phase Indium Zinc Tin Oxide Thin-Film Transistors with High Mobility and Excellent Uniformity

Improved Performance and Bias Stability of Indium‐Tin‐Zinc‐Oxide Thin‐Film Transistors Enabled by an Oxygen‐Compensated Capping Layer

Herein, the effects of oxygen‐compensated capping layer (CCL) on the electrical performance and stability of indium‐tin‐zinc‐oxide (ITZO) thin‐film transistors (TFTs) are investigated. Two different channel structures, namely, single and dual channels, are tested for the ITZO TFTs. The dual‐channel layer is created by depositing an oxygen CCL on the oxygen‐uncompensated channel layer (UCL), while the single‐channel layer consists only of the oxygen UCL. It is found that the oxygen CCL is critical for enhancing the electrical properties of dual‐channel ITZO TFT and its stability under different stress modes such as dynamic stress, positive bias temperature stress, and negative bias illumination stress. The dual‐channel ITZO TFT exhibits a saturation field‐effect mobility of 16.69 cm2 V−1s−1, a threshold voltage of 6.80 V, and a subthreshold swing of 0.22 V dec−1. Furthermore, it is revealed that the higher metal‐oxide concentration and fewer defects in the dual channel lead to enhanced electrical performance and stability of the device. This work demonstrates the potential of utilizing the oxygen CCL for the highly reliable operation of oxide semiconductor TFTs.

Indium Zinc Tin Oxide Bottom Electrode‐Based Flexible Indoor Organic Photovoltaics with Remarkably High Mechanical Stability

Indium Zinc Tin Oxide Bottom Electrode‐Based Flexible Indoor Organic Photovoltaics with Remarkably High Mechanical Stability

Indium Zinc Tin Oxide Bottom Electrode‐Based Flexible Indoor Organic Photovoltaics with Remarkably High Mechanical Stability

The demand for flexible indoor organic photovoltaic cells (OPVs) is growing dramatically due to their simple and practical use as a powering aid for various electronic gadgets connected to the Internet of Things. Due to the brittleness of inorganic material‐based transparent bottom electrodes and their incompatibility with flexible organic substrates, it is extremely difficult to limit the influence of mechanical stress on the stability of flexible OPV. In this regard, choosing a mechanically stable and highly conductive transparent conducting oxide (TCO) is crucial. Therefore, flexible OPVs are fabricated onto a flexible (polyimide) substrate coated with mechanically stable TCO indium zinc tin oxide (IZTO). Sheet resistance measurements and observations of scanning electron microscope images of IZTO film after 100 000 bending repetitions (bending radius: 5 mm) confirm the ultrahigh mechanical stability of the TCO. The sheet resistance of flexible IZTO electrode layers is increased by 9%, from 17.42 to 19.12 Ω sq−1. In addition, the impact of a large number of bending repetitions on film transmittance is minimal. The OPV shows ≈69% and ≈20% of its initial power conversion efficiency value after 100 000 bending repetitions for 1000 lx LED illumination and 1 sun conditions, respectively.

Effect of Single Spinel Phase Crystallization on Drain-Induced-Barrier-Lowering in Submicron Length IZTO Thin-Film Transistors

This study shows the effect of single spinel phase crystallization on drain-induced barrier lowering (DIBL) of indium-zinc-tin-oxide (IZTO) thin-film transistors (TFTs) with submicron channel length. The 0.9-μm-long amorphous IZTO (a-IZTO) TFT shows a poor DIBL of 318 mV/V. In contrast, a significant improvement in the DIBL is achieved in the single spinel phase IZTO (s-IZTO) TFT, which could be attributed to the suppression of lateral diffusion of oxygen vacancy (VO) and low VO defects through crystallization-induced enforcement of metal-oxygen bonds. Consequently, 0.9-μm-long s-IZTO TFT reveals a small DIBL of 92 mV/V as well as a high field-effect mobility of 90.1 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /Vs and a low subthreshold swing of 0.1 V/dec. In addition, reliability against external bias temperature stress is considerably improved through single-phase crystallization, leading to an insignificant threshold voltage shift of +0.4 (–0.4) V under positive (negative) bias stress with electric field of 2 (–2) MV/cm at 60 °C for 10,000 s, respectively, in the 0.9-μm-long s-IZTO TFT.

P‐3: Conductive Indium‐Tin‐Zinc Oxide Formed Using an Oxygen Plasma Treatment Through a Silicon Oxide Cover Layer

Indium‐tin‐zinc oxide (ITZO) covered with a silicon oxide layer can be made conductive when subjected to an oxygen plasma treatment. The resulting resistivity is sensitive to the thickness of the cover oxide, the plasma excitation power, and the treatment time. With 280 nm of cover oxide and 10 mins of treatment, the lowest resistivity achieved is 1.2 mΩ∙cm in a plasma biased with a radio frequency excitation power of 100 W and an inductively coupled plasma excitation power of 2000 W. The treatment has been deployed to form the source/drain regions of a self‐aligned, top‐gate ITZO thin‐film transistor.

Zinc oxide and indium tin oxide as embedding layers for ultrathin-silver-based transparent electrodes: A comparative study

The triple-layered structure comprising an ultrathin (∼10 nm) Ag layer embedded between two dielectric layers exhibits high visible light transmittance, electrical conductivity, and flexibility, and this triple-layered structure is thus considered as a promising candidate to replace the conventional single-layered indium tin oxide (ITO) transparent conductive electrodes in optoelectronic devices. While various dielectrics have been employed for the underlayer and overlayer, ITO and zinc oxide (ZnO) are the two common choices. In this study, we investigated the structural, electrical, optical, and thermal properties of triple-layered electrodes (dielectric underlayer/Ag/dielectric overlayer) comprising Ag, ZnO, and ITO; namely, ZnO/Ag/ZnO, ZnO/Ag/ITO, ITO/Ag/ITO, and ITO/Ag/ZnO electrodes, in which all layers were sputter-deposited at 293 K. The deposition of crystalline Ag onto crystalline ZnO and amorphous ITO surfaces exhibited distinctly dissimilar Ag nucleation dynamics, resulting in significant differences in the structural and thus electrical characteristics prior to Ag-layer-closure. After the formation of continuous Ag layers, the electrical conductivities became similar, whereas the optimized ITO/Ag/ZnO structure exhibited a considerably higher visible light transmittance than the other electrodes (with an average transmittance of 92.8%). Further, we found that the ZnO/Ag interface stability was significantly higher than that of the ITO/Ag interface during an electrically driven Joule heating process.

Enhanced Stability of Solution-Processed Indium–Zinc–Tin–Oxide Transistors by Tantalum Cation Doping

Highly stable metal oxide thin film transistors (TFTs) are required in high-resolution displays and sensors. Here, we adopt a tantalum cation (Ta5+) doping method to improve the stability of zinc–tin–oxide (ZnSnO) TFTs. The results show that Ta5+-doped TaZnSnO TFT with 1 mol% concentration exhibits excellent stability. Compared with the undoped device, the oxygen vacancy defects of TaZnSnO thin films reduce from 38.05% to 18.70%, and the threshold voltage shift (ΔVth) reduces from 2.36 to 0.71 V under positive bias stress. We attribute the improved stability to the effective suppression of the oxygen vacancy defects, which is confirmed by the XPS results. In addition, we also prepared TaInZnSnO TFT devices with 1 mol% Ta5+ doping concentration. Compared with the 1 mol% Ta5+-doped TaZnSnO TFTs, the μ increases two-fold from 0.12 to 0.24 cm2/Vs, and the Vth decreases from 2.29 to 0.76 V in 1 mol% Ta5+-doped TaInZnSnO TFT with an In:Zn:Sn ratio of 4:4:3, while the device remains highly stable with a ΔVth of only 0.90 V. The injection of Ta5+ provides a novel strategy for the enhancement of the stability in ZnSnO-based TFTs.

P‐1.4: Oxygen‐Plasma Induced Generation of Mobile Charge Carriers in Indium‐Tin‐Zinc Oxide

Mobile charge carriers can be generated in indium‐tinzinc oxide (ITZO) covered with a silicon oxide layer when subjected to an oxygen plasma treatment. The resulting ‍resistivity is sensitive to the thickness of the cover oxide, the plasma excitation power, and the treatment time. With 280 ‍nm of cover oxide and 10 mins of treatment, a low resistivity of 1.2 mΩ∙cm can be obtained in a plasma biased ‍with a radio frequency excitation power of 100 W and an inductively coupled plasma excitation power of 2000 W. ‍The treatment has been deployed to form the source/drain regions of a self‐aligned, top‐gate ITZO thin‐film ‍transistor.

Numerical simulation of Transparent Gate Thin-Film Transistor (TG-TFT) with varied gate materials for high-performance applications

This work presents the performance evaluation of Transparent Gate Thin-Film Transistor (TG-TFT) with the relative analysis of numerous materials such as Aluminum (Al), Gold (Au), Indium Tin Oxide (ITO), Zinc Oxide (ZnO), and Titanium Nitride (TiN). This work also aims to find the best suitable gate material on the TFT for high-performance applications through a solid thin film. It is observed from the outcomes that TG-TFT performance improves significantly with TiN gate in terms of mobility (∼4 times), switching ratio (ION/IOFF) by 46.42 %, and electric field by ∼ 29 % as compared to conventional gate material (Au). Further, surface potential and energy band profile have been shown. Therefore, the examination shows the perspective of TiN as gate materials that can be reused for requests in nanoelectronics tools and designing of IC boards owing to the better conductivity, robustness, and cheap nature of TiN along with proven results it can be used as a gate material.

Al-Doped ZnO Thin Films with 80% Average Transmittance and 32 Ohms per Square Sheet Resistance: A Genuine Alternative to Commercial High-Performance Indium Tin Oxide

In this study, a low-sophistication low-cost spray pyrolysis system built by undergraduate students is used to grow aluminum-doped zinc oxide thin films (ZnO:Al). The pyrolysis system was able to grow polycrystalline ZnO:Al with a hexagonal wurtzite structure preferentially oriented on the c-axis, corresponding to a hexagonal wurtzite structure, and exceptional reproducibility. The ZnO:Al films were studied as transparent conductive oxides (TCOs). Our best ZnO:Al TCO are found to exhibit an 80% average transmittance in the visible range of the electromagnetic spectrum, a sheet resistance of 32 Ω/□, and an optical bandgap of 3.38 eV. After an extensive optical and nanostructural characterization, we determined that the TCOs used are only 4% less efficient than the best ZnO:Al TCOs reported in the literature. This latter, without neglecting that literature-ZnO:Al TCOs, have been grown by sophisticated deposition techniques such as magnetron sputtering. Consequently, we estimate that our ZnO:Al TCOs can be considered an authentic alternative to high-performance aluminum-doped zinc oxide or indium tin oxide TCOs grown through more sophisticated equipment.

Long-memory retention and self-powered ultraviolet artificial synapses realized by multi-cation metal oxide semiconductors

We fabricated synaptic transistors based on IZTO-6 nanowires, which can achieve long-memory retention of long-term potentiation. Meanwhile, Al/IZTO-6/Ni devices indicate that MOS based synapses have self-powered capability.

Solution-processed amorphous zinc indium tin oxide thin-film transistors with high stability under AC stress

Amorphous zinc–indium–tin oxide thin-film transistors with various Zn : In : Sn ratios are investigated to improve AC stress stability by suppressing hot carrier effects in the channel layer.