Effect Of Indium Tin Oxide Research Articles

Electric tuning of plasmonic resonances in ultrathin gold nanoribbon arrays

Ultrathin plasmonic nanostructures offer an unparalleled opportunity for the study of light–matter interactions at the nanoscale and realization of compact nanophotonic devices. In this study, we introduce an ultrathin gold nanoribbon array and demonstrate an electric approach to actively tuning its plasmonic resonance, which leveraging the extreme light confinement capability in the ultrathin plasmonic nanostructure and a robust nanoscale electro-optical effect in indium tin oxide. Optimizing the design (to a total thickness as small as 12 nm for a 2-nm-thick gold nanoribbon array), we numerically demonstrate a spectral shift in the plasmonic resonance up to 36 nm along with an approximately 16% change in the transmission at a gate voltage below 1.7 V at the wavelength of 1.47 μm. This work presents progress towards electric tuning of plasmonic resonances in ultrathin metallic nanostructures for various applications including surface-enhanced spectroscopy, spontaneous emission enhancement, and optical modulation.

Analytical Modeling of Epsilon-Near-Zero Effect in Indium Tin Oxide and Its Application as an Optical Modulator

Analytical Modeling of Epsilon-Near-Zero Effect in Indium Tin Oxide and Its Application as an Optical Modulator

Broadband Modulation, Self‐Driven, and Self‐Cleaning Smart Photovoltaic Windows for High Efficiency Energy Saving Buildings

AbstractSmart photovoltaic windows (SPWs) are an emerging green technology presenting energy‐saving by combining solar irradiance regulation and solar energy harvesting. The SPWs integrating extraordinary energy‐saving performance, stable and controllable operational mode, and diverse functionality are essential for devising high efficiency energy‐saving buildings (ESBs). However, the attainment of such features has yet to be realized in current iterations of SPWs. Herein, a conceptual demonstration of a split‐type broadband modulation, self‐driven, and self‐cleaning SPWs is presented by coupling a silicon solar cell with a multifunctional chromogenic unit (MCU) for creating highly efficient ESBs. Within the multilayer structured MCU, thermal‐responsive polymer stabilized liquid crystal (PSLC) and VO2@SiO2 nanoparticles act as chromic component, enabling broadband light modulation. Thanks to the excellent electrothermal effect of indium tin oxide (ITO), the phase transition of PSLC and VO2@SiO2 nanoparticles can be induced by the electrical power output generated by the silicon solar cell. Therefore, the transparency of SPWs can be manipulated according to the occupant's preference during the daytime. Moreover, a superhydrophobic SiO2 coating provides SPWs with self‐cleaning capability which effectively reduces water resource consumption and eliminates the inconvenience of window cleaning, while providing occupants with a clear view even in complex weather conditions.

Model development of lattice-matched p-GaInP/i-GaAs/n-GaInP hetero-junction solar cell and its performance optimization

We report an analytical model for our proposed lattice-matched hetero-junction p-GaInP/i-GaAs/n-GaInP solar cell with the incorporation of AlInP cap layer and MgF2/TiO2 anti-reflection region supported by numerical data obtained using SENTAURUS TCAD. We investigate the impact of intrinsic layer thickness, cap layer thickness, compositional variation of gallium in GaInP alloy used in p- and n-regions of pin solar cell and also studied the effect of indium tin oxide (ITO) anode contact on photovoltaic performance of solar cell in terms of performance matrices i.e., open circuit voltage (Voc), short circuit current density (Jsc), fill-factor and power conversion efficiency (PCE). Also the performance of the proposed solar cell is optimized by judiciously choosing intrinsic layer thickness, and cap layer thickness. Our proposed device featuring 2.1-μm thick i-layer, 156-nm thick cap layer with Ga0.5In0·5P/GaAs active region yields a PCE of 19.89% which turns out to be 67% improvement as compared to the conventional solar cell enabling the proposed design attractive for photovoltaic applications.

Compact TE-pass polarizer based on lithium-niobate-on-insulator assisted by indium tin oxide and silicon nitride

An indium tin oxide (ITO) and silicon nitride (Si3N4) assisted compact TE-pass waveguide polarizer based on lithium-niobate-on-insulator is proposed and numerically analyzed. By properly designing the ITO and Si3N4 assisted structure and utilizing the epsilon-near-zero effect of ITO, the TM mode is strongly confined in the ITO layer with extremely high loss, while the TE mode is hardly affected and passes through the waveguide with low loss. The simulation results show that the polarizer has an extinction ratio of 22.5 dB and an insertion loss of 0.8 dB at the wavelength of 1.55 μm, and has an operating bandwidth of about 125 nm (from 1540 nm to 1665 nm) for an extinction ratio of > 20 dB and an insertion loss of < 0.95 dB. Moreover, the proposed device exhibits large fabrication tolerances. More notably, the device is compact, with a length of only 7.5 μm, and is appropriate for on-chip applications.

Electrically tunable metasurface for dual-band spatial light modulation using the epsilon-near-zero effect.

Electro-tunable metasurfaces have attracted much attention for the active control of incident light at the nanoscale by engineering sub-wavelength meta-atoms. In this Letter, for the first time, to the best of our knowledge, a grating-assisted dual-band metasurface for spatial light modulation is reported that can operate in two crucial telecommunication wavelength bands, i.e., C-band and O-band. The proposed device consists of a silicon-nitride nanograting on top of a silicon-indium-tin-oxide (ITO)-alumina-gold stack. Effective medium theory combined with a modal analysis is used to study the guided-mode resonance dips at 1.55 µm and 1.31 µm in the reflectance spectra. We leverage the epsilon-near-zero effect of ITO by applying an external bias voltage to introduce large modal loss, which leads to the disappearance of the resonance dips at those wavelengths. We obtain a high modulation depth of ∼22.3 dB at 1.55 µm and ∼19.5 dB at 1.31 µm with an applied bias of -4 V and -5 V, respectively. Thus, the proposed metasurface may help to realize dual-band active nanophotonic devices.

Semitransparent Printable Mesoscopic Perovskite Solar Cells for Tandem Solar Cells

The boosting efficiency of perovskite solar cells (PSCs) has evoked the interest in applying them in tandem structures, especially perovskite/silicon tandem solar cells. However, the tandem solar cells still face concerns about stability, upscaling, and cost‐effectiveness on the path to commercialization. Herein, an innovative tandem architecture based on the printable mesoscopic perovskite solar cells is proposed. By investigating the effects of indium tin oxide (ITO) particle size, annealing temperature, and dispersant on the performance of ITO mesoporous films, screen‐printable mesoscopic ITO electrode with an electron mobility of 7.5 cm2 V−1 s−1 and an average visible transmittance of over 80% is successfully obtained. The screen‐printed mesoporous titania, zirconia, and ITO are used as a scaffold and a semitransparent PSC with a champion power conversion efficiency of 9.38% is fabricated infiltrated with perovskites. Further, a perovskite/silicon tandem device which can remain stable for &gt;720 h is demonstrated, highlighting the potential of screen‐printed inorganic scaffold structure in tandem photovoltaic technique.

Effect of ITO Content on Properties of Functional Graphene Coating on Cotton Fabric

In order to investigate the effect of indium tin oxide (ITO) on the performance of graphene functional coating on cotton fabric, different contents of ITO were added to the graphene coating system, and the effects of ITO content and curing time on various properties of graphene coating were studied. The results showed that the ITO particles adsorbed on the graphene sheets and filled the gaps between the graphene sheets, forming a dense conductive network, which could further improve the conductive performance of the functional coatings. When ITO content was 1.2%, the resistivity of the coating reached the lowest 1.8 Ω·cm, and the overall ultraviolet transmittance and reflectance were the lowest. With the increase of ITO content, the infrared reflectance will first decrease and then slowly increase, but the infrared reflectance is all below 0.5%. When the curing time reached 90 s, the resistivity and UV transmittance of cotton fabric coating decreased. With the extension of curing time, the coating on infrared reflectivity gradually increased, but the infrared reflectivity of the overall < 1%.

All-dielectric multifunctional transmittance-tunable metasurfaces based on guided-mode resonance and ENZ effect

Electrically tunable metasurfaces open new doors for manipulating the phase, amplitude and polarization of light in ultrathin layers. Compared with metal assisted metasurfaces, all-dielectric transmission metasurfaces—with outstanding feature of low loss, especially incorporating with new electro-optical materials—show great potential for the next generation flat optics. In this study, by combining the epsilon-near-zero effect in indium tin oxide (ITO) with guided-mode resonance, we propose novel electrically tunable all-dielectric metasurface architectures with versatile functions for widespread potential application. The inserted periodic ITO and hafnium oxide layers sandwiched in silicon act as two metal-oxide-semiconductor capacitors in a single period to disturb the resonance wavelength in the near-infrared spectral range under the voltage applied. For the one-dimensional structure, the transmittances of this metasurface at 1512 and 1510 nm change 20 and −14 dB under 0∼5 V bias voltage, respectively. In addition, the bilayer structure performs well in double-waveband applications, indicating that more layers can support more operation wavebands. Meanwhile, the two-dimensional structure works as a polarization insensitive device when setting the same structural parameters in both orthogonal directions. The proposed architecture, with various merits including ultra-compact size, high-speed and complementary metal-oxide-semiconductor compatibility, provides a multifunctional and multi-degree-of-freedom design, as well as enormous potential applications in more complicated flat optics.

STUDI IKATAN HIDROGEN PADA ORIENTASI MOLEKUL DISPERSE RED-1 DENGAN METODE PVD BERBANTUAN MEDAN LISTRIK

Organic molecules with a conjugated chain structure such as the Disperse Red-1 (DR-1) molecule are known as potential materials for photonic device applications. The aim of this research is to study the surface effect of Indium Tin Oxide (ITO) substrate and the external electric field of 2.6 MV / m in regulating the orientation of the DR-1 film molecules on the surface of the ITO substrate. The fabrication method used is the PVD (Physical Vapor Deposition) method assisted by an external electric field. This method is a modification of the conventional PVD method which is equipped with the addition of an external electric field (E) in the chamber. The film was made on the surface of the ITO substrate with the deposition of DR-1 molecules in a variation of the external electric field, namely zero field and E = 3.3 MV / m. The films were analyzed and characterized using XRD (X-Ray Diffraction) spectroscopy. The X-ray diffraction measurement analysis showed that the DR-1 molecules were arranged in an orderly manner parallel to the surface of the ITO substrate, indicating an indication of the strong surface effect of the ITO substrate from the hydrogen bonding of the DR-1 molecule with the ITO substrate. The results of spectroscopic measurements show that with an increase in the external electric field, there is an increase in the effect of aggregation of molecules arranged in an orderly manner perpendicular to the surface of the ITO substrate.

The Effect of Carrier Distribution on Performance of ENZ-Based Electro-Absorption Modulator

Recently, epsilon-near-zero (ENZ) has been emerging as an important field of research which is the study of light-matter interactions in the presence of materials with zero permittivity. Since in many scientific works the uniform model of carrier distribution of Indium tin oxide (ITO) has been utilized, we want to investigate ENZ effect in ITO material and the effect of accurate carrier distribution on the performance of a modulator. For this reason, an electro-absorption (EA) modulators with a new configuration based on silicon slot modulator with indium thin oxide material is proposed. To study the effect of ENZ effect in ITO, the semiconductor model (realistic model) is utilized to model the carrier distribution in the ITO material. In this model, there is not any assumption. As a result, by applying the gate voltage, the insertion loss is increased 1.61 dB/μm in comparison with unbiased conditions. Also, the uniform model is used. Compared with the realistic model, the extinction ratio and figure-of-merit significantly enhance based on the uniform model, but the trends of results like insertion loss are so far from the realistic model. It can be found that the realistic model is reliable and the results are closer to reality.

Nonlinear optical re-orientation and photoacoustic properties of indium tin oxide nanoparticles

Abstract The nonlinear optical Kerr effect of indium tin oxide (ITO) nanoparticles (NPs) was investigated using continuous wave laser beams. ITO NPs were synthesized using the sol-gel method and were prepared as a colloid and a thin film. The structural and optical properties of the synthesized particles were characterized by X-ray diffraction analysis, transmission electron microscopy and UV–visible spectroscopy. The energy band gap was found to be 3.45 eV. The nonlinear optical properties of these NPs were measured by two sources: one He–Ne laser beam and a diode laser beam at wavelengths of 632.8 nm and 450 nm, respectively. For the He–Ne laser beam, the obtained nonlinear refractive index was found to be n 2 = + 1.7 × 10 − 7 c m 2 W , which its plus sign indicates that the main nonlinear refractive phenomenon involved was the optical re-orientation effect due to the electric dipole moment of the particles. The high nonlinear absorption of the particles at both wavelengths leads to the creation of intensity-dependent photoacoustic (PA) signals that are mainly in the audible range of sound frequencies. The sonic waves were within a frequency interval of 2–19 KHz. The ITO particles were present as NPs, which simultaneously show optical re-orientation and PA responses under continue wave (CW) laser irradiations. This research thus finds that ITO NPs are a good candidate for electro-optical sensors and applications.

Формирование кислородных пузырьков в стекле К-208 при электронном облучении

The formation of gas-filled bubbles, which is one of the indicators and quantitative criteria for radiation degradation of the surface layer of K-208 glass irradiated by 20-keV electrons, and the effect of ITO (Indium tin oxide) film deposited on the glass, are investigated. Using atomic force microscopy, the nucleation of oxygen bubbles in the surface layer of glass irradiated with a fluence (Φ) of the order of 1015 cm–2 at a particle flux density (φ) of 2·1010 cm–2·s–1 was detected. Gas-filled bubbles appear on the surface of samples with an ITO film at Φ ≥ 4·1015 cm–2 in smaller amounts but larger sizes than on glass without a film. The formation of oxygen bubbles is explained by the formation of a negative charge region in the surface layer of the irradiated glass, in the field of which sodium ions migrate, which plays a key role in the release of non-bridge oxygen atoms. Migration and aggregation of liberated oxygen atoms in defective places in the glass grid leads to the formation of gas-filled bubbles.

Exploring the Optical Dynamics in the ITO/As2Se3 Interfaces

In this work, the effects of indium tin oxide (ITO) substrates on the structural, compositional, optical dielectric and optical conduction properties of arsenic selenide thin films are investigated. The As2Se3 films which are prepared by the thermal deposition technique under vacuum pressure of 10−5 mbar exhibit an induced crystallization process, improved stoichiometry, increased optical transmittance in the visible range of light and increased dielectric response in the infrared range of light upon replacement of glass substrates by ITO. The ITO/As2Se3 interfaces exhibit conduction and valence band offset values of 0.46 eV and 0.91 eV, respectively. The experimental optical conductivity spectra are theoretically reproduced with the help of the Drude–Lorentz approach for optical conduction. In accordance with this approach, owing to the improved crystallinity of the arsenic selenide, the deposition of As2Se3 onto ITO substrates increases the drift mobility value from ∼ 17.6 cm2/Vs to 34.6 cm2/Vs. It also reduces the density of free carriers by one order of magnitude. The ITO/As2Se3/C heterojunction devices which are tested as band filters which may operate in the frequency domain of 0.01–3.0 GHz revealed low pass filter characteristics below 0.35 GHz and band pass filter characteristics in the remaining spectral range.

Electrochromic Effect of Indium Tin Oxide in Lithium Iron Phosphate Battery Cathodes for State-of-Charge Determination.

In this article, we discuss the origin of an optical effect in lithium iron phosphate (LFP) battery cathodes, which depends on the electrical charge transferred into the battery. Utilizing indium tin oxide (ITO) as an electrode additive, we were able to observe a change in reflectivity of the cathode during charging and discharging with lithiation and delithiation being clearly visible in the form of lithiation fronts. Further investigations using in situ video microscopy and in situ Raman spectroscopy on test cells with an optical window indicate that ITO additionally acts as an electrochromic marker within the LFP cathode. This enhances the optical effect due to local potentials around the lithiation fronts, which enables the voltage-dependent reflectivity of the ITO to be visible in the LFP cathode. Structural analysis with scanning electron microscopy and X-ray crystallography is presented as well. The observed effect allows for novel battery research methods and for a possible commercial application as a sensor for state-of-charge estimation.

A novel self-heating zinc oxide/indium tin oxide based hydrogen gas sensor: Dual sensing mode of hydrogen gas detection

A novel self-heating hydrogen gas sensor based on zinc oxide nanorods coated on indium tin oxide was fabricated. This sensor utilizes Joule heating effect of indium tin oxide to generate heat, while ZnO acts as a variable resistor to regulate the amount of electric current that passes through indium tin oxide layer upon exposure to oxygen and hydrogen gas. The gas sensor was capable of detecting very low concentration of H2 in air. Hence, for the first time, a new way of gas detection based on sensor temperature variation as the sensing mode was demonstrated.

Multi-layer MOS capacitor based polarization insensitive electro-optic intensity modulator.

In this study, a multi-layer metal-oxide-semiconductor capacitor (MLMOSC) polarization insensitive modulator is proposed. The design is validated by numerical simulation with commercial software LUMERICAL SOLUTION. Based on the epsilon-near-zero (ENZ) effect of indium tin oxide (ITO), the device manages to uniformly modulate both the transverse electric (TE) and the transverse magnetic (TM) modes. With a 20μm-long double-layer metal-oxide-semiconductor capacitor (DLMOSC) polarization insensitive modulator, in which two metal-oxide-semiconductor (MOS) structures are formed by the n-doped Si/HfO2/ITO/HfO2/ n-doped Si stack, the extinction ratios (ERs) of both the TE and the TM modes can be over 20dB. The polarization dependent losses of the device can be as low as 0.05dB for the "OFF" state and 0.004dB for the "ON" state. Within 1dB polarization dependent loss, the device can operate with over 20dB ERs at the S, C, and L bands. The polarization insensitive modulator offers various merits including ultra-compact size, broadband spectrum, and complementary metal oxide semiconductor (CMOS) compatibility.

Indium Tin Oxide Based Dual-Polarization Electro-Optic Intensity Modulator on a Single Silicon Waveguide

For high-speed optical transmission, polarization-division-multiplexing (PDM) is a promising technic to double the link capacity. However, most of on-chip PDM systems include a polarization beam splitter, a polarization rotator, and two modulators, which are costly and complex for integration. In this study, a novel dual-polarization electro-optic intensity modulator is proposed that is based on a single silicon waveguide with indium tin oxide (ITO) cladding. The design is validated by numerical simulation with commercial software Lumerical Solution. Based on the epsilon-near-zero effect of ITO, the device, on a single waveguide, manages to modulate simultaneously transverse electric (TE) and transverse magnetic (TM) modes with independent electrical driving signals. With a 75 μ m-long silicon rib waveguide, the extinction ratios (ERs) of both TE and TM modes can be around 15 dB, and the nonuniformity is around 0.5 dB. The 3 dB modulation bandwidths are 57.8 GHz and 65.9 GHz for TE and TM modulation, respectively. Within 1 dB ER nonuniformity, the device can operate at E -, S -, and C -band, which distinguishes itself by achieving wavelength-division-multiplexing compatible PDM and with only one single waveguide. To our best knowledge, the concept of independent and simultaneous dual-polarization modulation on a single waveguide is proposed for the first time. The modulator offers various merits including ultracompact size, high speed, and complementary metal oxide semiconductor (CMOS) compatibility.

Role of ITO nanoparticles embedded into electrospun ITO nanofibers

Both crystallization and molecular density are significant to achieve high electrical conductivity of transparent electrodes. Herein, we investigated the embedding effects of indium tin oxide (ITO) nanoparticles (NPs) into ITO nanofibers (NFs) synthesized by utilizing an electrospinning technique from ITO precursor solutions. We found that the ITO NPs might act as nucleation seeds that initiate crystallization of ITO, evidenced by flake-like morphologies which cannot be observed without ITO NPs. XRD measurements reveal that the ITO is crystalline with a higher degree and the size of ITO crystallites increases in the presence of ITO NPs embedded into NFs. Embedding ITO NPs leads to the formation of short fibers, but there is still large space between fibers as they are vertically stacked in the films, resulting in low electrical conductivity. Interestingly, a high ratio of ITO NPs enhances the electrical conductivity, as compared to a low ratio, which we attribute to the high fiber density on substrates due to the formation of shorter ITO NFs. Our results highlight that the ITO NPs influence not only the ITO crystallization but also the lengths of NFs. High electrical conductivity of NF films can be obtained by a high degree of crystallization and the optimum NF length that reduces spaces between NFs in the films.

Low driving voltage ITO doped polymer-dispersed liquid crystal film and reverse voltage pulse driving method.

This paper investigates the effects of indium tin oxide (ITO) powders on the driving voltage of polymer-dispersed liquid crystal (PDLC). The threshold voltage (Vth) and driving voltage (Vd) can be reduced through doping the ITO powders; in particular, the Vd is 5.8V when the weight ratio of ITO is 1.5wt. %. The relationship between the applied voltage and off-time of PDLC has been investigated; the lower the applied voltage, the shorter the off-time. On this basis, the reverse voltage pulse driving method was proposed; this driving method uses the driving signal to reduce the off-time of PDLC.