Properties Of Indium Tin Oxide Research Articles

The influence of laser-annealing pulse width on optical transparency and carrier dynamics of ITO thin films

Indium tin oxide (ITO) has important application in photoelectronic and photonic devices, demanding effective approach and appropriate parameters to modulate the ITO properties. The effects of laser annealing at 1064 nm with different pulse width (875 ps, 10 ns, and 300 ns) on optical and nonlinear optical properties of ITO films were investigated. Compared with 875 ps and 10 ns, laser annealing at 300 ns significantly improved the near-infrared transmittance of ITO films. The change arises from the elimination of oxygen vacancies and reduction of tin oxides, resulting in the decrease of carrier concentration. Finite element simulations indicate that laser annealing with pulse width of 875 ps and 10 ns have high instantaneous peak temperatures of 1128.5 K and 783 K, respectively, while the temperature accumulation between pulses is negligible. On the contrary, the laser annealing with a pulse width of 300 nshas lower peak transient temperature of 343 K but high static residence temperature of 973 K. The results reveal that the modification of ITO films depends more on the static average temperature rather than the instantaneous peak temperature. The modulation of carrier dynamics in both amplitude and temporal domain was demonstrated after 300 ns laser annealing, achieving ultrafast transient response approximately 150 fs. This work provides theoretical and experimental basis for us to select suitable laser conditions for directional annealing of ITO film to make it suitable for the applications of broad optical spectrum photovoltaic devices or ultrafast optical exchange for high-speed data processing.

Tailoring hole-selective contacts via self-assembled monolayers for advancing indoor organic photovoltaic and capacitor devices

Amidst the growing demand for transparent devices, the current research is centered on the advancement of technologies involving self-assembled monolayer (SAM)-treated transparent conductive electrodes. However, the detailed mechanisms governing surface energy reactions in these devices at the molecular scale remain unclear, underscoring the need for additional investigations. This study explored the effect of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) derivatives (MeO-2PACz, 2PACz, Br-2PACz) with a carbazole core on the properties of indium tin oxide (ITO) electrodes. On adsorbing 2PACz molecules onto the ITO surfaces, interfacial dipoles formed through chemisorption between the phosphonic acid oxygen and indium atoms, elevating the work function (WF). 2PACz treatment enhanced the electronic properties of the electrodes for indoor organic photovoltaics (OPV) and metal–insulator-metal (MIM)-capacitors.. The optimized Br-2PACz-based indoor OPVs achieved a remarkable 31.0 % power conversion efficiency and an excellent fill factor of 78.0 % under LED 1000 lx conditions. Furthermore, Br-2PACz-based MIM-capacitors exhibited a reduction in leakage current greater than 19,000 times compared to that of the TiN-electrode-based MIM-capacitors. These outstanding electronic device achievements were attributed to the elevated WFs of the electrodes achieved through the 2PACz treatment. This research underscores the manifold enhancements in device performance achieved through refined energy-level alignment stemming from the increased WFs facilitated by SAM integration.

Effect of In Layer Thickness on the Photoelectric Properties of Indium Tin Oxide (ITO)/In/ITO Multilayer Films

Indium Tin Oxide (ITO)/In/ITO films were fabricated using direct current magnetron sputtering technology to investigate the impact of the indium film on their photoelectric properties. The electrical performance analysis demonstrates a resistivity of 6.830 × 10–4 Ω·cm and an average transmittance of the thin film of 89.5% when the thickness of the indium layer is 12 nm. The ITO/In (12 nm)/ITO configuration exhibited the highest Figure of Merit of approximately 101.09 × 10–3 Ω–1. ITO and In share a similar interface, which promotes carrier mobility without causing light reflection, thereby enhancing transmittance. Based on resistivity, carrier concentration, and mobility, it is evident that sputtering the In layer can enhance the electrical properties of the ITO film.

Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions.

Indium tin oxide (ITO) has recently gained prominence as a photonic nanomaterial, for example, in modulators, tuneable metasurfaces and for epsilon-near-zero (ENZ) photonics. The optical properties of ITO are typically described by the Drude model and are strongly dependent on the deposition conditions. In the current literature, studies often make several assumptions to connect the optically measured material parameters to the electrical properties of ITO, which are not always clear, nor do they necessarily apply. Here, we present a comprehensive study of the structural, electrical, and optical properties of ITO and showed how they relate to the deposition conditions. We use guided mode resonances to determine the dispersion curves of the deposited material and relate these to structural and electrical measurements to extract all relevant material parameters. We demonstrate how the carrier density, mobility, plasma frequency, electron effective mass, and collision frequency vary as a function of deposition conditions, and that the high-frequency permittivity (ϵ∞) can vary significantly from the value of ϵ∞ = 3.9 that many papers simply assume to be a constant. The depth of analysis we demonstrate allows the findings to be easily extrapolated to the photonic characterisation of other transparent conducting oxides (TCOs), whilst providing a much-needed reference for the research area.

INVESTIGATION OF STRUCTURAL, OPTICAL, AND ELECTRICAL PROPERTIES OF ITO FILMS DEPOSITED AT DIFFERENT PLASMA POWERS: ENHANCED PERFORMANCE AND EFFICIENCY IN SHJ SOLAR CELLS

This article presents an investigation into the structural, optical, and electrical properties of Indium Tin Oxide (ITO) films that were deposited utilizing various plasma powers. The transmittance values in the visible region were measured, revealing that the ITO film deposited at 2050 W exhibited the highest transmittance (81%). Additionally, the sheet resistance values of all films were analyzed, indicating that the ITO film deposited at 2050 W had the lowest sheet resistance (64.9 Ω/sq). By means of XRD analysis, the structural properties of the films were meticulously scrutinized, and the distinctive diffraction peaks associated with the ITO films were successfully identified. Notably, the ITO film deposited at 2050 W demonstrated superior performance compared to the other films deposited using various plasma powers. Finally, we report a noteworthy efficiency of 17.03% achieved in the SHJ solar cell fabricated with the ITO film deposited at 2050 W on a 5x5 cm2 n-type Si substrate.

Static and transient optical properties of thin film indium tin oxide during laser excitation

The mechanisms of ultrafast laser-induced free electron generation and the effect of the free electrons on the transient optical properties in indium tin oxide is investigated by means of numerically solving rate equations and ultrafast transient experiments. A dynamical model for the transient optical properties of indium tin oxide thin films during excitation with an ultrashort laser pulse with fluences between 0.4 J cm−2 to 2.3 J cm−2 is developed and compared to pump probe microscopy during and after excitation with laser pulses. In the non-excited case, thin film interferences dominate the shape of the reflection spectrum. During laser excitation, (quasi-)free electron dynamics drastically alter the optical properties. The temporal evolution of the (quasi-)free electron density is numerically computed using rate equations for irradiation with laser pulses with various peak fluences for a pulse duration of 700 fs and a central wavelength of 1056 nm. We found that a thermal ionization term that takes electronic states within the band gap into account has to be considered to reproduce the reflectivities obtained by pump probe measurements. Additionally, we found that cascade ionization dominates the multiphoton ionization for indium tin oxide.

Optoelectronic and structural properties of ITO/Ag/ITO transparent electrodes using ultraviolet laser annealing

Indium tin oxide (ITO) is widely used in the optoelectronic industry as a transparent conductive oxide owing to its excellent optical and electrical properties. To improve the physical properties of ITO, highly conductive ITO/Ag/ITO multilayer electrodes were prepared using radio frequency (RF) magnetron sputtering at room temperature. Then, laser annealing was performed on the multilayer electrodes with scanning intervals of 0.01, 0.02, 0.05 and 0.1 mm. The structural properties of the multilayer electrodes were characterized by X-ray diffraction, and their optical and electrical properties were characterized by ultraviolet (UV) visible spectrophotometry and a four-point probe station, respectively. The results demonstrated that the multilayer films had a polycrystalline structure, and ITO (222) and Ag (111) preferred orientations were identified after laser annealing. In addition, the crystalline size of the Ag layers increased slightly, implying that the defect density within the Ag layers was reduced, resulting in a significant increase in its conductivity. A significantly low electrical resistivity of 5.35 [Formula: see text]/sq and high optical transmittance of 85% were achieved. The Haacke index value was [Formula: see text], which was much better than the value of [Formula: see text] before laser annealing.

Strongly Coupled Plasmon Polaritons in Gold and Epsilon-Near-Zero Bifilms.

Epsilon-near-zero (ENZ) polaritons in a thin transparent conducting-oxide film exhibit a significant electric field enhancement and localization within the film at frequencies close to their plasma frequency, but do not propagate. Meanwhile, plasmon polariton modes in thin metallic films can propagate for several microns, but are more loosely confined in the metal. Here, we propose a strongly coupled bilayered structure of a thin gold film on a thin indium tin oxide (ITO) film that supports hybrid polariton modes. We experimentally characterize the dispersion of these modes and show that they have propagation lengths of 4-8 μm while retaining mode confinement greater than that of the polariton in gold films by nearly an order of magnitude. We study the tunability of this coupling strength by varying the thickness of the ITO film and show that ultrastrong coupling is possible at certain thicknesses. The unusual linear and nonlinear optical properties of ITO at ENZ frequencies make these bifilms useful for the active tuning of strong coupling, ultrafast switching, and enhanced nonlinear interactions at near-infrared frequencies.

Influence of Post Processing on Thermal Conductivity of ITO Thin Films

This work presents the influence of post processing on morphology, thermal and electrical properties of indium tin oxide (ITO) thin films annealed at 400 °C in different atmospheres. The commercially available 170 nm thick ITO layers deposited on glass were used as a starting material. The X-ray diffraction measurements revealed polycrystalline structure with dominant signal from (222) plane for all samples. The annealing reduces the intensity of this peak and causes increase of (221) and (440) peaks. Atomic force microscopy images showed that the surface morphology is typical for polycrystalline layers with roughness not exceeding few nm. Annealing in the oxygen and the nitrogen-hydrogen mixture (NHM) changes shapes of grains. The electrical conductivity decreases after annealing except the one of layer annealed in NHM. Thermal conductivities of annealed ITO thin films were in range from 6.4 to 10.6 W·m-1·K-1, and they were higher than the one for starting material-5.1 W·m-1·K-1. Present work showed that annealing can be used to modify properties of ITO layers to make them useful for specific applications e.g., in ITO based solar cells.

Cost-effective equipment for surface pre-treatment for cleaning and excitation of substrates in semiconductor technology

This article presents a cost-effective ultraviolet-ozone cleaner (UV/O3 Cleaner) for surface pre-treatment of substrates in the field of semiconductor technology. The cleaner consists of two chambers, the upper one contains the electronics, including the time counter. The lower chamber contains the two UV sterilisation lamps and a UV reflector of anodized aluminium, which confines the area of high Ozone concentration in the area of interest. The device is successfully used for surface cleaning and modification of different materials. To this end, the two important wavelengths 253.7 nm (excitation of organic residues) and 184.9 nm (production of ozone from the atmospheric environment as a strong oxidant) were first detected. The effectiveness of UV/O3 cleaning is demonstrated by improving the properties of indium tin oxide (ITO) for OLED fabrication. The contact angle of water to ITO could be reduced from 90° to 3° and for diiodomethane, it was reduced from 55° to 31° within the 10 min of irradiation. This greatly improved wettability for polar and non-polar liquids can increase the flexibility in further process control. In addition, an improvement in wettability is characterized by measuring the contact angles for titanium dioxide (TiO2) and polydimethylsiloxane (PDMS). The contact angle of water to TiO2 decreased from 70° to 10°, and that of diiodomethane to TiO2 from 54° to 31°. The wettability of PDMS was also greatly increased. Here, the contact angle of water was reduced from 109° to 24° and the contact angle to diiodomethane from 89° to 49°.Article HighlightsWe report a cost-effective dry-cleaning device for surface cleaning and modification based on ultraviolet-ozone irradiation.Contact angle measurements show an increase of wettability for different materials due to surface modification.The UVO3 pre-treatment improves layer formation and optoelectrical properties of OLEDs.

Encapsulation of locally welded silver nanowire with water-free ALD-SbOx for flexible thin-film transistors

Transparent conductive electrodes are essential in the application of flexible electronics. In this work, we successfully demonstrated a novel strategy for improving mechanical/electrical properties of indium tin oxide (ITO)-free flexible silver nanowire (Ag NW) thin films. To reduce the contact resistance of Ag NWs, an ethanol-mist was used to weld the cross junction of wires at room temperature. The nano-welded Ag NWs (W-Ag NWs) were then coated with an aluminum-doped ZnO (AZO) solution, which significantly reduce the roughness of the Ag NW thin film. Finally, an ultrathin SbOx thin film of 2 nm was deposited on the film surface using a water-free low-temperature atomic layer deposition technique to protect the W-Ag NW/AZO layer from water or oxygen degradation. The treated Ag NWs have a high transmittance of 87% and a low sheet resistance of about 15 Ω/sq, which is comparable with the ITO electrode's property. After 1000 cycles of bending testing, the W-Ag NW/AZO/SbOx film practically retains its initial conductivity. Furthermore, the samples were immersed in a solution with pH values ranging from 3 to 13 for 5 min. When compared to untreated Ag NWs or those coated with AlOx thin films, W-Ag NW/AZO/SbOx had superior electrical stability. The W-Ag NW/AZO/SbOxlayer was integrated as a gate electrode on low-power operating flexible Ti-ZnO thin film transistors (TFTs). The 5% Ti-ZnO TFT has a field-effect mobility of 19.7 cm2 V s−1, an Ion/Ioff ratio of 107, and a subthreshold swing of 147 mV decade−1.

Photo-engineered optoelectronic properties of indium tin oxide via reactive laser annealing

Transparent conductive oxides are appealing materials for optoelectronic and plasmonic applications as, amongst other advantages, their properties can be modulated by engineering their defects. Optimisation of this adjustment is, however, a complex design problem. This work examined the modification of the carrier transport properties of sputtered tin-doped indium oxide (ITO) via laser annealing in reactive environments. We relate the optical modifications to the structural, compositional, and electronic properties to elucidate the precise mechanisms behind the reactive laser annealing (ReLA) process. For sufficiently high laser fluence, we reveal an ambient-dependent and purely compositional modulation of the carrier concentration of ITO thin films. Hereby, we demonstrate that ReLA utilises the precise energy delivery of photonic processing to enhance the carrier mobility and finely tune the carrier concentration without significantly affecting the crystal structure. Exploitation of this phenomena may enable one to selectively engineer the optoelectronic properties of ITO, promising an alternative to the exploration of new materials for optoelectronic and photonic applications.

How Optical and Electrical Properties of ITO Coated Willow Glass Affect Photonic Curing Outcome for Upscaling Perovskite Solar Cell Manufacturing

Indium tin oxide (ITO) coated Willow glass is an excellent substrate for roll-to-roll manufacturing of perovskite solar cells (PSCs) but can have large variability in its optical and electrical properties. Photonic curing uses intense light pulses instead of heat to process materials and can facilitate faster processing speeds in roll-to-roll manufacturing to upscale the production of PSCs. Since the entire film stack can absorb light and contributes to the photonic curing outcome, the substrate materials’ properties play an integral role. Here, we present the effect of ITO transmittance on the photonic curing of nickel nitrate sol-gel precursors into nickel oxide and consequently the performance of PSCs fabricated with only photonic curing and no thermal annealing. Unexpectedly, ITO samples processed by photonic curing show improved optical and electrical properties.

Sputtering under Mild Heating Enables High-Quality ITO for Efficient Semi-Transparent Perovskite Solar Cells

Semi-transparent perovskite solar cells (ST-PSCs) are promising in building-integrated photovoltaics (BIPVs) and tandem solar cells (TSCs). One of the keys to fabricate high-performance ST-PSCs is depositing efficient transparent electrodes. Indium tin oxide (ITO) is an excellent transparent conductive oxide with good light transmittance and high conductivity. However, the high sheet resistance of ITO sputtered at room temperature leads to the low fill factor (FF) and poor power conversion efficiency (PCE) of the ST-PSCs. Here, we study the effect of the sputtering temperature on the properties of ITO and the performance of ST-PSCs. We find that when the sputtering temperature increases from the room temperature to 70°C, the crystallinity of the sputtered ITO gradually improves. Therefore, the sheet resistance decreases and the corresponding device performance improves. However, once the sputtering temperature further increases over 70°C, the underlying hole transport layer will be damaged, leading to poor device performance. Therefore, the optimized mild heating temperature of 70°C is applied and we obtain ST-PSCs with a champion PCE of 15.21%. We believe this mild heating assisted sputtering method is applicable in fabricating BIPVs and TSCs.

Tailoring properties of indium tin oxide thin films for their work in both electrochemical and optical label-free sensing systems

This work is devoted to the identification properties of indium tin oxide (ITO) thin films responsible for their possible application in combined optical and electrochemical label-free sensing systems offering enhanced functionalities. Since any post-processing would make it difficult to identify direct relation between deposition parameters and properties of the ITO films, especially when deposition on temperature-sensitive substrates is considered, the films were deposited using reactive high power impulse magnetron sputtering (HiPIMS) at low temperature and with no post-deposition annealing. We focused mainly on the impact of reactive gases, such as oxygen or nitrogen introduced to the process chamber, on control over plasma parameters and subsequently properties of the films. The properties of the films were investigated using X-ray diffractometry, spectroscopic ellipsometry, four-point probe, and cyclic voltammetry. For presenting optical sensing capabilities, the tailored ITO films in addition to silicon and glass wafers were also deposited on the core of optical fibers to induce the lossy-mode resonance (LMR) phenomenon. The existence of specific deposition conditions resulting in ITO film properties offering both high-quality electrochemical and LMR responses has been experimentally proven. It has been found that the crystalline structure of ITO plays a key role in the determination of both the sensing capabilities. Finally, label-free sensing of antibody-antibody interactions in both optical and electrochemical domains for the sensor with tailored ITO film has been shown.

Electrical Properties Of The OLED With Convergence Relation By Surface Treatment Methods

ITO (indium-tin-oxide) is used widely as the anode electrode in organic electroluminescence devices (OLEDs). Several studies have dealt with the effect of ITO chemical treatment but to the OLEDs performance have not been considered the effect of this treatment. We were present here results regarding these effect.We studies of the effect of surface treatments on the properties of ITO substrate. We were performed chemical treatment with RCA and Aqua regiaof the OELDs. Since we will understand the properties of OELDs, we were performed Fowler-Nordheim tunneling. The buffer layer and ITO surface treatment were performed to increase the efficiency of the OLEDs. As a result, we were obtained conform the surface properties of ITO can be significantly changed by chemical treatment. The oxygen decrease produced by chemical treatment lead to increase of oxygen vacancies. We conformed that the oxygen vacancies role on increasing carrier injection. A study on the cause of improving the performance of the device using the surface treatment and the usingthe buffer layer will be of great help in understanding the relationship between the properties of the ITO substrate and the organic electroluminescent device.

Highly transparent and conductive ITO substrates for near infrared applications

Indium tin oxide (ITO) is the most widely used transparent conductor in applications such as light emitting diodes, liquid crystal devices, touch screens, and photovoltaic cells. So far, its use has mainly been limited to the visible range (380 nm–750 nm), as it reflects at longer wavelengths and, consequently, its transmission is low. Here, we introduce a simple technique, based on high temperature annealing, which can reduce reflection in the near-infrared range (750 nm–2400 nm). With an optimized set of parameters, we were able to modulate the ITO properties and achieve a high transmission, greater than 80% including substrate contribution, at telecommunication wavelengths (C-band, 1530 nm–1565 nm) while still maintaining high electrical conductivity (resistivity <1.9 × 10−4 Ω cm). By using the newly developed infrared ITO transparent conductor, we demonstrate quantum dot solar cells with 27.7% enhancement in external quantum efficiency at the first exciton peak (1650 nm), and liquid crystal switching devices with 25% enhancement in transmission, with respect to device counterparts incorporating commercially available ITO.

Исследование влияния особенностей конструкции установки магнетронного распыления на электрические и оптические свойства пленок оксида индия-олова

The influence of the relative position of the magnetron and the substrate on the electrical and optical properties of the forming indium tin oxide (ITO) layers is demonstrated. The reasons for this behavior are considered and the role of oxygen in the onset of inhomogeneity of the properties of ITO films is shown. It is shown that, in the growth mode without additional oxygen addition, the resistivity of ITO films differs by an order of magnitude ((2−14)·10^−2 Ohm·cm) for different positions of the substrate on the substrate holder along the radius in the range of 0−14cm. In this case, absorption spectra are observed differences in the shape of the short-wavelength region of the spectrum. The addition of an insignificant (0.1sccm) amount of oxygen to the working chamber during the growth of the oxide leads to a significant increase in the homogeneity of the electrical and optical properties of ITO

Differences in ITO Interface Characteristics Change According to the Formation of Aromatic-Ring and Aliphatic Self-Assembled Monolayers

Herein, we confirm the performance difference according to the structure of self-assembling monolayer (SAM) and investigate the characteristics of the indium tin oxide (ITO) surface when ITO substrates are deposited by (3,3,3-trifluoropropyl)trimethoxysilane (F-3SAM) and (heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane (F-10SAM) having different chain lengths with trifluoromethyl group as terminal functional group, as well as SAM benzoic acid (BA) and 2-naphthoic acid (NA) with benzene ring forms. Through these, it is possible to control the wetting properties, surface roughness, and work function of the ITO surface. Wetting characteristics, average roughness, and changes in work function of the ITO surface were characterized by contact angle measurement, atomic force microscopy (AFM), and UV photoelectron spectroscopy (UPS). The measured contact angles were 41.1°, 82.25°, and 118° for the bare ITO, NA, and F-10SAM, respectively, the average roughnesses of the SAM-modified surfaces were 1.377, 1.033, and 0.838 nm for the bare ITO, NA, and F-10SAM, respectively. The work function of the ITO surface modified with NA and F-10SAM increased from 0.21 and 0.36 eV to 5.01 and 5.16 eV, respectively. As a result, the surface properties of ITO were better for aliphatic SAM than for aromatic ring SAM.

Electrical and optical properties linked to laser damage behavior in conductive thin film materials

Epsilon-near-zero-materials (ENZ-materials) and their unique properties are key to the successful integration and miniaturization of optical components. Novel concepts, which promise significant progress in this field of research, such as optical switches and thin film electro-optical modulators, are possible when the electrical and optical properties of ENZ-materials are carefully exploited. To achieve a greater understanding of these properties, in this paper the electrical conductivity, optical transmittance, as well as absorption of thin indium tin oxide films, are investigated and linked to their laser-induced damage threshold in the ultra-short pulse regime. To the best of the authors’ knowledge, this is the first concise study linking the electrical properties of indium tin oxide to its properties regarding high-power laser applications.