Indium Tin Oxide Research Articles

Enhanced Photoelectrochemical Water Splitting of In2S3 Photoanodes by Surface Modulation with 2D MoS2 Nanosheets.

Photoanodes with ample visible-light absorption and efficient photogenerated charge carrier dynamics expedite the actualization of high-efficiency photoelectrochemical water splitting (PEC-WS). Herein, we fabricated the heterojunction nanostructures of In2S3/MoS2 on indium-doped tin oxide glass substrates by indium sputtering and sulfurization, followed by the metal-organic chemical vapor deposition of 2D MoS2 nanosheets (NSs). The photocurrent density of In2S3/MoS2 was substantially enhanced and higher than those of pristine In2S3 and MoS2 NSs. This improvement is due to the MoS2 NSs extending the visible-light absorption range and the type-II heterojunction enhancing the separation and transfer of photogenerated electron-hole pairs. This work offers a promising avenue toward the development of an efficient photoanode for solar-driven PEC-WS.

Design of Optically Transparent Coded Metamaterial Based on an Indium Tin Oxide Film Using Deep Learning for Radar Cross-Section Reduction

Design of Optically Transparent Coded Metamaterial Based on an Indium Tin Oxide Film Using Deep Learning for Radar Cross-Section Reduction

Refractive index sensing characteristics of PCF-SPR based on dual-plasmon materials

Abstract In this paper, a photonic crystal fiber (PCF) refractive index sensor based on surface plasmon resonance (SPR) with dual plasmonic materials (indium tin oxide and gold) is proposed. We innovatively designed a dual-core PCF structure and pore arrangement effectively enhancing the coupling effect. Using two different plasma materials, phase matching is achieved at two different wavelengths for the evanescent and surface plasmon waves, resulting in dual resonance peaks. The refractive index sensing is accomplished by measuring the dual-peak resonance shift, which expands the detection wavelength and RI detection ranges. The sensor can detect analytes with refractive indices ranging from 1.32 to 1.43 at wavelengths between 0.4 um and 1.4 um. We optimized the photonic crystal fiber structure and studied the sensing performance of the sensor, improving its sensitivity. Simulation results indicate that the designed PCF sensor exhibits outstanding maximum dual-peak shift sensitivity (DPSS), reaching up to 28,000 RIU-1, along with maximum amplitude sensitivity (AS) and wavelength sensitivity (WS) of 18,500 RIU-1 and 34,500 RIU-1, respectively, in the direction of y-polarization. Furthermore, the sensor achieves high resolution, and the figure of merit (FOM) values can reach up to 5.134×10-7 and 2758. Consequently, the proposed sensor can provide high-precision and extensive-range measurements of solution refractive indices within the visible and infrared light spectrum, and it holds potential application prospects in numerous fields, such as food safety testing and chemical substance detection.

Compositional Optimization of Sputtered SnO2/ZnO Films for High Coloration Efficiency

We performed an electrochromic investigation to optimize the composition of reactive magnetron-sputtered mixed layers of zinc oxide and tin oxide (ZnO-SnO2). Deposition experiments were conducted as a combinatorial material synthesis approach. The binary system for the samples of SnO2-ZnO represented the full composition range. The coloration efficiency (CE) was determined for the mixed oxide films with the simultaneous measurement of layer transmittance, in a conventional three-electrode configuration, and an electric current was applied by using organic propylene carbonate electrolyte cells. The optical parameters and composition were measured and mapped by using spectroscopic ellipsometry (SE). Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) measurements were carried out to check the SE results, for (TiO2-SnO2). Pure metal targets were placed separately from each other, and the indium–tin-oxide (ITO)-covered glass samples and Si-probes on a glass holder were moved under the two separated targets (Zn and Sn) in a reactive argon–oxygen (Ar-O2) gas mixture. This combinatorial process ensured that all the compositions (from 0 to 100%) were achieved in the same sputtering chamber after one sputtering preparation cycle. The CE data evaluated from the electro-optical measurements plotted against the composition displayed a characteristic maximum at around 29% ZnO. The accuracy of our combinatorial approach was 5%.

Enhanced analog switching and neuromorphic performance of ZnO-based memristors with indium tin oxide electrodes for high-accuracy pattern recognition.

This study systematically investigates analog switching and neuromorphic characteristics in a ZnO-based memristor by varying the anodic top electrode (TE) materials [indium tin oxide (ITO), Ti, and Ta]. Compared with the TE materials (Ti and Ta), memristive devices with TEs made of ITO exhibit dual volatile and nonvolatile switching behavior and multistate switching characteristics assessed based on reset-stop voltage and current compliance (ICC) responses. The polycrystalline structure of the ZnO functional layer sandwiched between ITO electrodes was confirmed by high-resolution transmission electron microscopy analysis. The current transport mechanism in the ZnO-based memristor was dominated by Schottky emission, with the Schottky barrier height modulated from 0.26 to 0.4V by varying the reset-stop voltage under different ICC conditions. The long-term potentiation and long-term depression synaptic characteristics were successfully mimicked by modulating the pulse amplitudes. Furthermore, a 90.84% accuracy was achieved using a convolutional neural network architecture for Modified National Institute of Standards and Technology pattern categorization, as demonstrated by the confusion matrix. The results demonstrated that the ITO/ZnO/ITO/Si memristor device holds promise for high-performance electronic applications and effective ITO electrode modeling.

Microfluidic device with three-dimensional microtip electrodes for efficient capture and concentration of bacteria-sized microparticles using dielectrophoresis

Microfluidics-based systems have gained considerable attention in the lab-on-chip field owing to their ability to separate, concentrate, and analyze microparticles. Concentrating microparticles is crucial for the high-sensitivity measurement of biomarkers in the analysis of cells or bacteria. This study presents a microfluidic chip using dielectrophoresis (DEP) to capture bacterial microparticles. The chip features a vertically arranged microtip electrode and an indium tin oxide (ITO) electrode, enhancing the electric field concentration effect and enabling optical analysis of the collected particles. The device was designed and fabricated using microfabrication techniques that incorporate a patterned array of microtip electrodes on a polydimethylsiloxane (PDMS) substrate. Experimental studies and numerical simulations were conducted to evaluate the device performance. The fabricated device was applied to the concentration of fluorescent beads with various variables such as particle size, frequency, voltage, and flow rate. The experimental results demonstrated the successful trapping and concentration of microparticles using DEP forces. The recovery rates of the 2.29 µm and 4.42 µm PS beads, when introduced at a flow rate of 1 μL/min and subjected to an applied alternating current (AC) voltage of 200 kHz and 10 Vpp at the microtip electrode, were measured to be 85.50±2.69 % and 91.83±0.63 %, respectively. Additionally, to assess the applicability of the microtip electrode-based DEP device proposed here for bacteria concentration, capture experiments were conducted using Escherichia coli, demonstrating a recovery rate performance of 77.93±7.31 %. These findings highlight the potential of the proposed microfluidic chip for the concentration and measurement of bacteria, such as E. coli.

Enhanced thermal stability photophysical properties of photoselective PMMA/ITO nanohybrid films for greenhouse cooling in hot climates

The current research proposed innovative photoselective greenhouse cooling films made from PMMA/ITO nanohybrids, incorporating varying concentrations of Indium tin oxide nanocrystals (ITO NCs) and the fluorescent organic dye Lumogen F Red300, utilizing the solvent casting method. The morphology and structure were examined using transmission electron microscopy (TEM) and X-ray diffraction (XRD), demonstrating good homogeneity and amorphous nature. The impact of different ITO NC concentrations on physical properties was examined through differential scanning calorimetry (DSC), optical absorption, transmission, reflection, fluorescence, and Fourier transform infrared (FT-IR) spectroscopy. Integrating ITO NCs into the PMMA matrix showed enhanced thermal insulation capabilities of PMMA films while maintaining their transparency to photosynthetically active radiation (PAR). Maintaining this balance is crucial because it enables the films to selectively filter and reflect infrared radiation leading to lower greenhouse temperatures while still allowing the essential light needed for plant growth to pass through. This research is particularly significant for Sustainable Development Goals (SDGs) 2 and 13, especially in hot, water-scarce regions, as it protects plants from thermal stress, promotes growth, and supports food security in developing countries.

Effect of surface electromagnetic wave treatment on the refractive properties of thin films based on indium tin oxides with laser-deposited single-walled carbon nanotubes

Effect of surface electromagnetic wave treatment on the refractive properties of thin films based on indium tin oxides with laser-deposited single-walled carbon nanotubes

The Effect of Indium Tin Oxide Nanoparticles (ITO NPs) Incorporated with ZnO NPs based on Structural, Optical and Flexible Dye Sensitized Solar Cells (FDSSCs) Application.

This study aimed to investigate the impact of zinc oxide nanoparticles (ZnO NPs) doped with indium tin oxide nanoparticles (ITO NPs) on polymer-based dye-sensitized solar cells (DSSCs). The ZnO NPs and ITO NPs were synthesized using the sol-gel and co-precipitation methods, respectively. They were then characterized and applied for dye-sensitized solar cells of a polymer-based substrate. Transmission electron microscopic (TEM) analysis revealed the presence of hexagonal structures and small spherical nanoparticles. The mean diameter of the ZnO NPs was found to be 15.22 ± 0.11 nm, while the ZnO NPs doped with ITO NPs (ZnO NPs/ITO NPs) had a mean diameter of 14.54 ± 0.16 nm. The effects of the ITO NPs on the ZnO NPs were evaluated, and it was found that these ITO NPs enhanced the performance of the flexible electrode DSSCs. After the addition of ITO NPs, the power conversion efficiency (PCE) of the ZnO NPs was boosted to be three times higher than that of the ZnO NPs DSSCs without ITO NPs. Similarly, the ultraviolet (UV) band exhibited a red shift, resulting in a lower band gap and reduced charge transfer resistance, which can enhance the PCE of the DSSCs. The polyethylene terephthalate (PET)/indium tin oxide (ITO) (PET/ITO) substrate conductive polymer showed positive outcomes for DSSCs. The PCE value for ZnO NPs was 2.198 ± 0.14%, while for ZnO NPs/ITO NPs, it was 6.680 ± 0.12%. This work achieved remarkable and competitive performance when compared to a solid (indium tin oxides/glass)-based substrate.

Enhanced Threshold Voltage and Improved Subthreshold Swing Using NiOX/ITO Reverse Bias Gated Diamond pMOS

An increase in the device performance of diamond‐based p‐type metal–oxide–semiconductor (pMOS) transistors using a combination of p‐type nickel oxide and n‐type indium tin oxide (NiOX/ITO) reverse bias diode as the gate dielectric is reported. Negative threshold voltage pMOS transistors are desirable for digital circuits and power applications for fail‐safe operation. A Schottky gate‐based conventional diamond pMOS transistor suffers from many limitations, including a positive threshold voltage (VT). Herein, it is experimentally demonstrated that NiOX/ITO gate dielectric with Al gate contact circumvents many critical limitations, providing a negative threshold voltage of −1.2 V, improved subthreshold slope of 145 mV dec−1, current ON/OFF ratio >107, and peak gate leakage current reduction >103. An Al/NiOX‐based control gate structure shifts the VTH negative with improvements in crucial device performances. Adding a reverse bias junction through the Al/ITO/NiOX heterointerface with the Al metal gate further improves performance. The measured device characteristics are explained in a common framework of energy band diagram for all the devices.

Polarized and Directional Electroluminescence from Organic Light‐Emitting Devices by Using a Bifunctional Meta‐Electrode

AbstractOrganic light‐emitting devices (OLEDs) with polarized and directional emission are highly desired for their promising applications in optical imaging, optical communication, and immersive visual technologies. Existing implementation methods based on free space bulk optical elements suffer from significant power loss, limiting their practical applications. Here, a bifunctional meta‐electrode is proposed by integrating a metasurface consisting of Ag periodic corrugations onto the indium tin oxide (ITO) anode to simultaneously realize the functions of charge carrier injection and photon management in the OLEDs. Highly polarized and directional light emission is demonstrated while maintaining a high device efficiency using the meta‐electrode. The electroluminescence with a polarization extinction ratio of 5 is achieved by judiciously engineering the polarization‐dependent Purcell factor of the resonant cavity constructed by the meta‐electrode. Meanwhile, the directional light emission with a divergence angle of 10° can be obtained by the efficient out‐coupling of surface plasmon‐polariton mode. The light beam can be collimated in one direction by using 1D nanogratings and in two directions by using 2D nanopillars, respectively.

Effect of current spreading layer on Internal Quantum efficiency and optical power of flip chip gallium nitride LEDs with circular contacts

The unique properties of the Indium Tin Oxide (ITO) make it an excellent choice as a current spreading layer in Flip Chip Light Emitting Diodes (FCLEDs) and other optoelectronic devices. Herein, the performance of FCLEDs is analyzed by a precise mathematical model for the current spreading length (Ls) produced by the ITO layer under circular-shaped contacts. The expressions are formulated without approximations using ABC-model for extracting the Internal Quantum Efficiency (IQE, ηint), optical power (Pint) and Emission Intensity (EI). The thickness (tITO) and resistivity (ρITO) of the ITO layer are varied for different current densities, and their adverse effects on IQE are determined. At lower current densities, IQE increases with thickness and decreases for high resistivity of the ITO layer. At higher current densities, there is a gradual decrease in IQE irrespective of the ITO layer presence due to “Efficiency Droop”. The IQE in the proposed work is 82 % at a thickness of 50–200 nm and current density of 8 A/cm2, and the optical power is around 40 mW, showing good agreement with the experimental data, making it feasible for future high-performance FCLEDs.

Effect Of Annealing Temperature On The Optical And Structural Properties Of Zinc-Doped Cd2SnO4 Thin Films Prepared By Dip-Coating Method

As demand for solar PV modules steadily increases studies on cheaper alternative TCO materials, with low resistivity and high transmittances in the visible spectrum to replace ITO are been undertaken. Among TCO materials considered as alternative to Indium Tin Oxide (ITO) is Cd2SnO4, owing to its availability in large quantities at relatively lower costs. Studies on optical properties of N2 and F2 doped Cd2SnO4 films have revealed increased transmittance 99%, and reduced band gap 3.3 eV. On the other hand Fe doped films have been observed to exhibit higher refractive indices, extinction and absorption coefficients with lower transmittance and optical band gap. Although studies have been carried out on Zinc doped Cd2SnO4 films, the effect of annealing temperature on the properties of the films have not been reported. This study investigated the effect of annealing temperature on the optical and structural properties of Zinc-doped Cd2SnO4 films. Thin films of Zincdoped Cd2SnO4 were prepared by mixing 0.1 M Cadmium Acetate with 0.1 M Tin II Chloride in ratio 1:1 to prepare Cd2SnO4 which was doped with 0.1 M Zinc Nitrate then dip-coated on clean glass substrates. The coated substrates were dried at room temperature and annealed in air the films annealed at 350 o C, 400 o C and 450 o C for 90 minutes Optical transmittance and reflectance were measured in wavelength range 200-1200 nm and with the results: prominent XRD peak oriented in the (2 0 0) direction, transmittance of 78.7% at 700 nm wavelength, absorption coefficient of 3.891 - 5.591 x 104 cm-1 , extinction coefficient of 0.1852 - 0.2126, refractive indices of 1.983-2.121 at 588 nm wavelength and band gap values range 3.45-3.65 eV. Annealing was observed to reduce refractive index and does not affect transmittance therefore doesn’t enhance suitability of films as TCO materials for Photovoltaic applications.

An ultra-sensitive bimetallic based electrochemical sensor for analysis of total iron, total dissolved iron, and granular iron in coastal water

Different iron species play crucial roles in the biogeochemical cycle, so their determination is important. Electrochemical methods are among the most promising and easiest methods for the rapid on-site determination of different iron species. In this study, a new electrode—Au–Bi/ITO—based on the commercial indium tin oxide (ITO) electrode was etched and functionalized with bismuth nanoparticles (BiNPs) and gold nanoparticles (AuNPs) nanocomposites for voltammetric analysis of iron species in coastal water. After etching, the ITO electrode exhibits a higher number of attachment sites for the nanomaterials, thereby improving the stability of the resulting electrode, and the introduction of the nanomaterials improves the sensitivity of the electrode, making it easier to realize on-site detection. Under the synergistic effect of the two nanomaterials, the Au-Bi/ITO electrode showed excellent performance for the determination of different iron species in coastal water. Under the optimal conditions, the Au-Bi/ITO electrode peak current was linear in the concentration range from 5 nM to 1.5 μM with an ultralow detection limit of 1.4 nM. The results are consistent with certified values when the electrode is used for the determination of Fe(III) in certified reference materials. In summary, the Au-Bi/ITO electrode, with its high stability and sensitivity, has been successfully used for the direct determination of different Fe(III) species in coastal water via cathodic stripping voltammetry. This electrode is simple to prepare, easy to use, economical, and highly promising for future applications involving the rapid on-site detection of different iron species.

Incorporation of Gold Nanoparticle into ZnO Electron Transport Layer to Improve Performance of Hybrid Bulk Heterojunction Solar Cell

Abstract We have investigated the effect of localized surface plasmon resonance (LSPR) from gold nanoparticles incorporated into the electron transport layer (ETL) of zinc oxide (ZnO) on charge carrier transport in order to improve the performance of inverted hybrid bulk-heterojunction solar cells. Synthesis of gold nanoparticles capped by 3-mercaptopropionic acid (AuMPA) and oleylamine (AuOA) was carried out by use of the reduction method and the fabrication of solar cell device with the configuration of ITO/ZnO:AuNPs/P3HT:PCBM/PEDOT:PSS/Ag was done by spin coating and thermal evaporation techniques. The absorbance spectra show a plasmonic peak of AuMPA in solution at 521 nm, while AuOA has a plasmonic peak at 531 nm, with both solutions showing a red-wine color. In our investigation, the incorporation of AuMPA about 2.65wt% or AuOA about 3.5 wt% in the ZnAc solution is quite stable. With the addition of 1.77 wt% AuMPA, the fabricated devices show a significant improvement at short circuit condition (JSC) from 46.67 mA/cm2 to 83.11 mA/cm2, resulting in an increase in power conversion efficiency (PCE) from 5.64% to 9.00% under the illumination of 100 mW/cm2 simulated solar irradiation. While the AuOA addition of 2.65 wt%, the JSC increased from 22.67 mA/cm2 to 44.12 mA/cm2 along with an improvement of PCE from 2.71% to 5.32%. The experiment results suggest that the electron mobility or charge carrier transport to the indium tin oxide (ITO) cathode is improved by the local electric field enhancement around the zinc oxide (ZnO) electron transport layer due to the effect of gold nanoparticles (AuNPs).

High-Performance Intrinsically Stretchable Organic Photovoltaics Enabled by Robust Silver Nanowires/S-PH1000 Hybrid Transparent Electrodes.

Intrinsically stretchable organic photovoltaics (is-OPVs) hold significant promise for integration into self-powered wearable electronics. However, their potential is hindered by the lack of sufficient consistency between optoelectronic and mechanical properties. This is primarily due to the limited availability of stretchable transparent electrodes (STEs) that possess both high conductivity and stretchability. Here, a hybrid STE with exceptional conductivity, stretchability, and thermal stability is presented. Specifically, STEs are composed of the modified PH1000 (referred to as S-PH1000) and silver nanowires (AgNWs). The S-PH1000 endows the STE with good stretchability and smoothens the surface, while the AgNWs enhance the charge transport. The resulting hybrid STEs enable is-OPVs to a remarkable power conversion efficiency (PCE) of 16.32%, positioning them among the top-performing is-OPVs. With 10% elastomer, the devices retain 82% of the initial PCE after 500 cycles at 20% strain. Additionally, OPVs equipped with these STEs exhibit superior thermal stability compared to those using indium tin oxide electrodes, maintaining 75% of the initial PCE after annealing at 85°C for 390 h. The findings underscore the suitability of the designed hybrid electrodes for efficient and stable is-OPVs, offering a promising avenue for the future application of OPVs.

Self-powered Schottky barrier photodetectors based on P3HT:PC61BM bulk heterojunction films

By employing the classic system poly(3-hexylthiophene-2,5-diyl): [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM), organic bulk heterojunction films were applied on an indium tin oxide substrate using a one-step spin-coating method, without requiring any complex manufacturing processes, to obtain self-powered photodetectors (PDs) with a simple preparation process. The fullerene material was introduced to create a bulk heterojunction film with proper phase separation and greatly enrich the donor/acceptor dissociation interface, thus improving the high exciton binding energy and short exciton diffusion distance. The built-in electric field formed by the Schottky junction at the interface between the active layer and electrode can enhance the separation of excitons and the transport of charge carriers, realizing optical detection without external energy sources. Moreover, femtosecond transient absorption was employed to investigate the exciton dynamics in organic films and analyze the working mechanism of self-powered detection performance. The long-lived behavior of carriers and the formation of charge transfer states were further verified, which contributed to the enhanced performance of the device. As a result, the self-powered PD-based Schottky bulk heterojunction presents a high light on/off ratio of over 104 (0 V) and fast response speed with rise and decay times of 33 and 36 µs, respectively, under a 532 nm light illumination. These results provide theoretical and experimental verification of this technique for the development of self-powered PDs in the field of organic materials.

Tunable optically transparent graphene–ITO patterning-based millimeter-wave absorber

In this work, we demonstrated a multilayer millimeter-wave absorber capable of tuning the absorption frequency while simultaneously maintaining the optical transparency. It comprises indium tin oxide (ITO) as the bottom ground plane deposited over polyvinyl chloride (PVC) substrate over which a patterned ITO layer is formed. Above this ITO layer, a PVC spacer is put to isolate the upper graphene sandwich structure (GSS) comprising of two patterned graphene mediums separated by a diaphragm paper. The configuration shows the tunability of reflectance minima (which correspond to high absorptance of ≥ 98 %) in a frequency range of 92.5–97.5 GHz due to the adjustable bias voltage applied to GSS. Additionally, the designed absorber demonstrates adequate shielding effect, generally required for both commercial and military applications in the stated frequency range. This simultaneously configurable and optically transparent device has potential in multispectral and smart stealth technologies, particularly 6G applications.

Design and investigation of indium tin oxide-based transparent broadband microwave absorbers

This paper presents the design of a novel wideband transparent microwave absorber based on indium tin oxide (ITO). The absorber adopts a multilayer structure, with the top layer composed of a nested square structure made of ITO material, an intermediate dielectric layer of polyvinyl chloride (PVC), and a bottom layer of polyethylene terephthalate (PET) coated with ITO as the reflector. By optimizing structural parameters such as the thickness of the ITO film and the dimensions of the spacer layer, efficient broadband microwave absorption exceeding 90% is achieved within the frequency range of 2.43 to 5.67 GHz, while simultaneously meeting requirements for optical transparency and broadband performance. Simulation experiments and theoretical analyses demonstrate excellent polarization and incident angle stability of the absorber structure. Finally, samples are fabricated using screen printing technology, and free-space testing results are consistent with simulation predictions, validating the feasibility of the design.

Optical Study on Co-Sensitization of Betanin Dye with Cadmium Sulfide to Fabricate Dye Sensitized Solar Cell

Natural dyes are low-cost, eco-friendly, readily available and have optical characteristics which render them useful in energy research. The titanium tetra isopropoxide precursor can be employed using sol-gel synthesis to get titanium dioxide nanoparticles (TiO2 NPs). The FESEM analysis confirmed the deposition of TiO2 NPs on Indium Tin Oxide (ITO) substrate, which is necessary for the photo-conversion mechanism to produce electricity. One of the natural dyes that is extracted from red beets is known as betanin dye (Bd). Due to their aligned energy levels, Bd and cadmium sulfide (CdS) are used together to provide effective optical characteristics, making them suitable as dye sensitizers. The presence of Cd-S, C-N and hydroxyl groups assigned to 500, 1633, and 3300 cm-1 respectively, was demonstrated by the FTIR analysis. The energy gap of 2.16, 2.13 and 2.2 eV for Bd, CdS and Bd-CdS composite was estimated using Tauc's plot and UV-visible spectra demonstrated maximum absorbance at 485, 510 and 528 nm, respectively. The Bd absorbs broad light in visible region due to the addition of CdS. The major charge-transport phenomenon in dye-sensitized solar cells (DSSC) involves an increase in photo-current density, due to its luminous nature. However, the recombination of charge carriers prevents the overall performance of the DSSCs. The power conversion efficiency of the DSSC constructed from Bd dye and Bd-CdS composite was 0.234% and 0.367%, respectively. This optical investigation suggests co-sensitization as a sure-fire method to improve the efficiency of DSSCs extracted from natural dyes, making them reliable for future indoor applications.