Indium Oxide Nanoparticles Research Articles

Terahertz nonvolatile in situ electrically erasable-rewritable photo-memory based on indium oxide/PEDOT:PSS.

A terahertz (THz) nonvolatile in situ electrically erasable-rewritable photo-memory based on indium oxide (In2O3) nanoparticles is reported. The In2O3/PEDOT:PSS/quartz sample increases its conductivity and attenuates its THz transmission under optical excitation. When this optical excitation is terminated, the modulated THz transmission recovers to its original value in an air environment slightly. The modulated THz transmission recovered more rapidly with increasing bias voltage. Nonvolatile digital information storage is enabled when the In2O3/PEDOT:PSS/quartz structure is encapsulated in nitrogen. The photo-memory can be rewritten after in situ electrical erasure. The results show that in situ electrically erasable terahertz nonvolatile rewritable photo-memories are feasible.

Electrical conduction in gold nanoparticles embedded indium oxide films: a crossover from metallic to insulating behavior

Electrical conductivity of indium oxide and gold nanoparticles incorporated indium oxide films grown by dc sputtering have been studied in the temperature range 1.5 to 300 K. Films with 0, 6 and 12% gold nanoparticle volume fraction exhibit metallic nature in the temperature interval 1.5 to 20 K, with conduction being governed by electron–electron interaction. Films with 20% gold nanoparticle volume fraction showed insulating nature and the conduction was governed by variable range hopping mechanism in the temperature range 1.5 to 50 K. Furthermore, a crossover from Efros–Shklovskii to Mott type was observed around 15 K. The transition from metallic to insulating nature in spite of the larger gold nanoparticle volume fraction is attributed to the inhibition of oxygen vacancies by Au species during film growth. At higher temperatures, all films exhibit activated conduction.

Improved CO gas detection of Si MOSFET gas sensor with catalytic Pt decoration and pre-bias effect

This paper investigates carbon monoxide (CO) gas sensing performance in a silicon metal-oxide semiconductor field effect transistor (Si MOSFET)-based gas sensor having a structure in which a floating-gate (FG) and a control-gate (CG) are interdigitated in a horizontal direction. The sensing material, indium oxide (In2O3) nanoparticles, is formed by an inkjet printing process between the FG covered with an insulator stack and exposed CG. Decorating the sensing layer with catalytic Pt and applying pulsed pre-bias are introduced as a method to improve CO gas sensing characteristics of the MOSFET sensor. First, CO gas sensing performance with Pt concentration and operating temperature is studied. The sensing performance is measured at 200 °C mainly by applying pulses to the CG. The response, response and recovery times of the MOSFET sensor are significantly enhanced with catalytic Pt decoration. In this work, 5% Pt decoration shows the best sensing characteristics. Response and recovery times are improved by 65% and 70%, by applying a pre-bias of 2 V and −2 V to the CG during response and recovery, respectively.

The active modulation of flexible terahertz tube

We demonstrated a flexible polyimide terahertz tube that can modulate Terahertz (THz) wave efficiently based on indium oxide (In2O3) nanoparticle. The transmission of the THz pulse can be modulated using optical control over 0.2 to 2.6 THz, and the modulation depth reached up to 14%. By combining nano-indium oxide layer with metal periodic metamaterial structure, the modulation was optimized to 35%. The results show that a photo-excited tunable terahertz modulator can be realized by irradiating the structure under different intensity of the laser beam.

Double-shelled hollow rods assembled from nitrogen/sulfur-codoped carbon coated indium oxide nanoparticles as excellent photocatalysts

Excellent catalytic activity, high stability and easy recovery are three key elements for fabricating efficient photocatalysts, while developing a simple method to fabricate such photocatalysts with these three features at the same time is highly challenging. In this study, we successfully synthesized double-shelled hollow rods (DHR) assembled by nitrogen (N) and sulfur (S)-codoped carbon coated indium(III) oxide (In2O3) ultra-small nanoparticles (N,S-C/In2O3 DHR). N,S-C/In2O3 DHR exhibits remarkable photocatalytic activity, high stability and easy recovery for oxidative hydroxylation reaction of arylboronic acid substrates. The catalyst recovery and surface area were well balanced through improved light harvesting, contributed by concurrently enhancing the reflection on the outer porous shell and the diffraction in the inside double-shelled hollow structure, and increased separation rate of photogenerated carriers. Photocatalytic mechanism was investigated to identify the main reactive species in the catalytic reactions. The electron separation and transfer pathway via N,S-codoped graphite/In2O3 interface was revealed by theoretical calculations.

Terahertz read-only multi-order nonvolatile rewritable photo-memory based on indium oxide nanoparticles

We investigate terahertz (THz) read-only multi-order nonvolatile rewritable photo-memory based on indium oxide (In2O3) nanoparticles. Optical excitation of an In2O3/quartz sample increases its conductivity, which attenuates its THz transmission. When the optical excitation is terminated, the modulated THz transmission can recover back to its original value in air. However, the THz transmission shows no obvious change over a long-term when In2O3/quartz is encapsulated in an inert gas (nitrogen). Multi-order nonvolatile digital information storage is obtained at different light intensities, and the photo-memory can be rewritten after thermal annealing. Different THz transmissions are used as coded signal units, which are programmed to store information. These results show that THz read-only multi-level nonvolatile rewritable photo-memory can be realized.

Plasmon-induced charge separation at the interface between ITO nanoparticles and TiO2 under near-infrared irradiation.

Plasmon-induced charge separation (PICS) by continuous electron injection from plasmonic compound nanoparticles to a semiconductor was achieved by using solid-state cells based on tin-doped indium oxide (ITO) nanoparticles with a short capping agent and a TiO2 film. The cells extended the PICS range to longer wavelengths and exhibited photoresponses to 1500-2200 nm near-infrared light.

Paper-Based, Hand-Painted Strain Sensor Based on ITO Nanoparticle Channels for Human Motion Monitoring

Paper-based strain sensors have attracted attention as a cost-effective and environmentally friendly approach to wearable electronic devices. This paper proposes a paper-based strain sensor created solely using hand-painting, which is a simple, equipment-free process utilized in green electronics. Commercial printing paper is coated with polydimethylsiloxane diluted with heptane, which provides moisture resistance and mechanical robustness while increasing the hydrophobicity of the surface. The electrodes and conduction channels are fabricated using a pencil for graphite deposition and a brush for the deposition of tin-doped indium oxide nanoparticles, respectively. With a gauge factor of 41.98 in tensile strain tests and 21.36 in compressive strain tests, our strain sensor exhibits a good sensitivity that is similar to that of previously reported paper-based sensors. We also demonstrate that our proposed strain sensor can be used as a weak motion detection device for humans and robots.

Microstructural and Optical properties of Indium Oxide Nanoparticles

Abstract The nanoparticles of indium oxide have been synthesized through the sol-gel method. Indium Oxide in the nanoparticles form is expected to offer greater sensitivity and also greater response time owing to the enhanced surface-to-volume ratios. The structural analysis of indium oxide has been done through X-ray diffraction studies (XRD). The consequences of structural analysis show the construction of Indium Oxide nanoparticles in single crystalline phase not showing any impurity. The optical absorption spectra of Indium Oxide nanoparticles recorded by UV-VIS spectrophotometer in the range of 270 to 700 nm have been presented. Structural and compositional studies of the indium oxide nanoparticles have been done by scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDAX) related to the SEM (JEOL, Japan).The EDAX spectra of In2O3 NPs shows the existence of In and O ions. The UV-Visible absorption and Photoluminescence emission spectra of In2O3 nano powders were done in the range of 370–700 nm using UV Vis Spectrophotometer (Perkin Elmer Lambda -35) and Photoluminescence Spectra (F-4600) respectively in the range of 300-500 nm.

Synthesis and Characterization of Advanced Nanomaterials: Tin-Doped Indium Oxide (ITO) and Platinium Deposited on Tin-Doped Indium Oxide (Pt/ITO).

This article describes the synthesis and characterization of tin-doped indium oxide (ITO) and platinum nanoparticles deposited on ITO. For different calcination temperatures, the tin-doped indium oxide nanoparticles (ITO NPs) were synthesized successfully by a nonaqueous sol-gel method with indium acetylacetonate and tin bis(acetylacetonate) dichloride in oleylamine as the precursors. The ITO sample that calcinated at 500 °C exhibited a spherical morphology with a narrow range of the particle size distribution (15-20 nm). Moreover, the electrical conductivity of the sample (1.242 S/cm) was higher than many different non-carbon supports. In addition, 20% platinum nanoparticles (Pt NPs) were also deposited uniformly on the ITO supports via chemical reduction process using NaBH4 as the reducing agent. The size of Pt NPs was about 5 nm and the crystalline structure of ITO supports remained unchanged.

Structure and Morphological Properties of In2O3 Nanostructure Prepared by Pulse Laser Ablation Method

A colloidal indium oxide (In 2 O 3 ) nanoparticles (NPs) were synthesized pulsed laser ablation (PLA) of indium plate placed on the bottom of the quartz vessel containing (3ml) of pure ethanol. The influence laser energy on the properties of the formed nano-particles were characterized by using atomic force microscopy (AFM), X-ray diffraction (XRD), Ultraviolet Visible (UV-Vis) technique, and electrical properties measurements. The XRD revealed the crystallization structure of In 2 O 3 nanoparticles and all the films having preferential orientation along (222) plane and intensity increases with increasing laser energy, The UV�Visible spectrum of the colloidal nanoparticles maximum absorbance show around the UV region, which indicates the formation of In 2 O 3 nanoparticles with energy gap about (3.6, 3.8 and 3.9) eV for different laser energy's (150, 300 and 500) mj respectively. The film conductivity decreased with increasing laser energy, while increasing in the the activation energy of In 2 O 3 nanopartical.

A novel dual-nano assisted synthesis of symmetrical disulfides from aryl/alkyl halides

Here, we have reported a novel approach towards dual-nano assisted synthesis of disulfides from coupling of alkyl/aryl halides and sulfur nanoparticles. The indium oxide nanoparticles as catalyst expedite the conversion and sulfur nanoparticle notably enhances the miscibility, providing a faster, high yielding and cost-effective process in ethanol-water system. The method has synthetic advantages in terms of mild reaction framework, catalyst regeneration, and absence of any sulfide or polysulfide linkage as by-product leading to a column free synthesis. A variety of alkyl, aryl and heteroaryl symmetrical disulfides are obtained in good to excellent yields up to exceeding 98%.

Nitrative DNA damage in cultured macrophages exposed to indium oxide.

Objectives: Indium compounds are used in manufacturing displays of mobile phones and televisions. However, these materials cause interstitial pneumonia in exposed workers. Animal experiments demonstrated that indium compounds caused lung cancer. Chronic inflammation is considered to play a role in lung carcinogenesis and fibrosis induced by particulate matters. 8-Nitroguanine (8-nitroG) is a mutagenic DNA lesion formed during inflammation and may participate in carcinogenesis. To clarify the mechanism of carcinogenesis, we examined 8-nitroG formation in indium-exposed cultured cells. Methods: We treated RAW 264.7 mouse macrophages with indium oxide (In2O3) nanoparticles (primary diameter: 30-50 nm), and performed fluorescent immunocytochemistry to detect 8-nitroG. The extent of 8-nitroG formation was evaluated by quantitative image analysis. We measured the amount of nitric oxide (NO) in the culture supernatant of In2O3-treated cells by the Griess method. We also examined the effects of inhibitors of inducible NO synthase (iNOS) and endocytosis on In2O3-induced 8-nitroG formation. Results: In2O3 significantly increased the intensity of 8-nitroG formation in RAW 264.7 cells in a dose-dependent manner. In2O3-induced 8-nitroG formation was observed at 2 h and further increased at 4 h, and the amount of NO released from In2O3-exposed cells was significantly increased at 2-4 h compared with the control. 8-NitroG formation was suppressed by 1400W (an iNOS inhibitor), methyl-β-cyclodextrin and monodansylcadaverine (inhibitors of caveolae- and clathrin-mediated endocytosis, respectively). Conclusions: These results suggest that endocytosis and NO generation participate in indium-induced 8-nitroG formation. NO released from indium-exposed inflammatory cells may induce DNA damage in adjacent lung epithelial cells and contribute to carcinogenesis.

Thermal and Optical Properties of In and In2O3 Nanoparticles Synthesized Using Pulsed Plasma in Water

We present small indium (In) nanoparticles with an average diameter of 4.5 nm synthesized by pulsed plasma in water. Slightly increased lattice constants and thermal stability of the tetragonal In are revealed by X‐ray diffraction analysis, Rietveld refinement, and thermogravimetric analysis. The highly crystalline body‐centered cubic indium oxide (In2O3) nanoparticles with an average diameter of 12 nm and various shapes (semispherical, semihexagonal, and semicubic) are obtained by annealing the as‐synthesized In nanoparticles at 450 °C. The bandgap energy of the In2O3 nanoparticles is 3.63 eV; the value is 25% higher than that of bulk In2O3 and comparable to those of In2O3 nanoparticles/thin films prepared by other methods, despite their smaller size.

Enhanced structural properties of In 2 O 3 nanoparticles at lower calcination temperature synthesised by co‐precipitation method

Indium oxide nanoparticles (In2O3 NPs) were formed by calcining the optimised as-prepared indium hydroxide (In(OH)3) NPs. The as-prepared In(OH)3 NPs were synthesised at optimal pH 10 through co-precipitation method at various calcination temperatures (200, 300, 400, 500, 600°C) for 2 h. Characterisation of the samples was performed by thermogravimetric (TGA and differential thermal, DTA) analysis, high-resolution transmission electron microscope (HRTEM), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy, and Raman spectroscopy. The complete conversion to In2O3 NPs was reached at 300°C. Besides, the crystallite size of In2O3 NPs calculated by William-Hall equation had the same trend with the values obtained from Scherrer equation. The HRTEM images also showed that the size of In2O3 NPs was within the range of 15–28 nm. Clearly, their work confirmed that the smallest In2O3 NPs (15 nm) with homogenous particle distribution were formed at a lower calcination temperature of 300°C.

Bi60In2O93 Nanoparticles: Photocatalytic Activity Investigation

Objective: Synthesis and characterization of bismuth indium oxide (Bi60In2O93) nanoparticles and their evaluation as new visible lightsensitive photocatalysts. Methods: Synthesis was achieved using a simple hydrothermal method at low temperature and the crystal structures and morphology of the prepared Bi60In2O93 nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Optical properties of the nanoparticles were measured by UV-visible spectroscopy and photocatalytic activity was tested by measuring their effects on rhodamine-B degradation under UVvisible and visible light. Results: The prepared samples had high crystallinity and were tetragonal. Bi60In2O93 nanoparticles exhibited strong photocatalytic activity under simulated sunlight. Nanoparticles prepared from a Bi:In mole ratio of 12:1 had the smallest size (~75 nm in diameter) and were the most uniform with good spherical morphology. These particles showed the strongest photocatalytic activity, including activity in the visible region. The possible mechanism for activity enhancement of Bi60In2O93 nanoparticles compared with Bi2O3 was investigated. The enhanced degradation of rhodamine-B, which is promoted by dye sensitization, is related to the higher crystallinity, unique tunnel structure, narrower band gap and special electron structure of the Bi60In2O93 nanoparticles. Conclusion: Bi60In2O93 nanoparticles show good promise as visible light-sensitive photocatalysts and for semiconductor development.

Alcohol gas sensors capable of wireless detection using In2O3/Pt nanoparticles and Ag nanowires

An unconventional method is developed to fabricate flexible and transparent sensors for real-time, wireless sensing of alcohol vapors using hybrid nanostructures of indium oxide and Pt nanoparticles (as an active channel) with random networks of metal nanowires (as electrodes and antennas). The hybrid structures of indium oxide and Pt nanoparticles present high response and selectivity for ethanol vapor sensing with detecting the blood alcohol concentration range corresponding to the license suspension or revocation in the Road Traffic Act of many countries (blood alcohol concentration 200 ppm). The integration of a Bluetooth system or an inductive antenna enables wireless operations of the alcohol sensor using smartphones for applications as wearable and hands-free devices with flexible, transparent film geometries. Furthermore, these sensor systems exhibit outstanding thermal reliabilities for their stable operations over wide temperature ranges between −40 °C and 125 °C, which can extend their practical use for automobile electronics. Such devices can be transferable onto diverse nonplanar surfaces including steering wheels and curved glasses of phones, which suggests substantial promise for their applications in next-generation automobile or wearable electronics.

Indium-oxide nanoparticles for RRAM devices compatible with CMOS back-end-off-line

We report on the fabrication and characterization of Resistive Random Access Memory (RRAM) devices based on nanoparticles in MIM structures. Our approach is based on the use of indium oxide (In2O3) nanoparticles embedded in a dielectric matrix using CMOS-full-compatible fabrication processes in view of back-end-off-line integration for non-volatile memory (NVM) applications. A bipolar switching behavior has been observed using current-voltage measurements (I-V) for all devices. Very high ION/IOFF ratios have been obtained up to 108. Our results provide insights for further integration of In2O3 nanoparticles-based devices for NVM applications.

Highly sensitive and flexible strain sensors based on patterned ITO nanoparticle channels

We demonstrate a highly sensitive and flexible bending strain sensor using tin-doped indium oxide (ITO) nanoparticles (NPs) assembled in line patterns on flexible substrates. By utilizing transparent ITO NPs without any surface modifications, we could produce strain sensors with adjustable gauge factors and optical transparency. We were able to control the dimensional and electrical properties of the sensors, such as channel height and resistance, by controlling the NP assembly speed. Furthermore, we were able to generate controlled gauge factor with values ranging from 18 to 157, which are higher than previous cases using metallic Cr NPs and Au NPs. The alignment of the ITO NPs in parallel lines resulted in low crosstalk between the transverse and longitudinal bending directions. Finally, our sensor showed high optical transmittance, up to ∼93% at 500 nm wavelength, which is desirable for flexible electronic applications.

Synthesis and magnetic properties of (Fe, Sn) co-doped In2O3 nanoparticles

The iron (Fe) and tin (Sn) co-doped indium oxide (In2O3) nanoparticles at different Fe doping concentrations were prepared by solid state reaction and studied for their structural, optical and magnetic properties. The XRD patterns confirmed the cubic structure of all the undoped and co-doped samples. The average crystallite size decreased on increasing from 41 to 32 nm by increase of Fe doping concentration from 5 to 15 at.%. The optical band gap of the samples was found to decrease from 2.89 to 2.77 eV by increasing the Fe dopant concentration. The magnetic properties of the nanoparticles were studied using vibrating sample magnetometer at room temperature and at 100 K by applying the field ±75,000 Oe perpendicular to the sample. The magnetization increased with increase of applied magnetic field and no saturation was observed in all the samples. The similar behavior was observed for the nanoparticles studied at 100 K.