Narrow Results

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide (ITO) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

The ITO film was deposited onto the glass substrate at room temperature by the inclination opposite target type DC magnetron sputtering equipment. An indium tin alloy (In₂O₃(90wt%)+SnO₂(10wt%)) target was used. The Total sputtering pressure was varied from 2.6×10^-1 to 8.3×10^-1Pa. The experimental result showed that the ITO film produced at room temperature had microstructure in which a X-ray diffraction peak is not clear, regardless of the total sputtering pressure. All the films showed a high optical transmittance. The ITO films prepared at low pressures gave low electrical resistivity. The elastic modulus and hardness of ITO films on various total sputtering pressures were increased with decreasing the total sputtering pressure and this tendency was similar to the change in electrical resistivity with decreasing the total sputtering pressure.

Nanocrystal indium tin oxide (ITO) thin films were grown by electron beam evaporation (e-beam). The ITO films were fabricated at substrate temperatures ranging from 100 to 400°C in O₂ partial pressure ranging from 0.10 to 100 mTorr. The surface morphology was monitored using atomic force microscopy (AFM). The charge in the surface morphology of ITO films was discussed in terms of grain size and crystallographic orientations. Grain size measurements of the solid dispersed and the AFM study for nanostructure showed that the oxides were in the nano range (20–30 nm). In general, the values of the optical bandgap for the films are consistently blue-shifted as compared with the crystal size. The average crystalline size determined from the shift of the optical gap were found to be in the range 20–30 nm, which is in excellent agreement with the data obtained from AFM. All ITO films average grain size was ~ 20 nm deposited by e-beam evaporation. The average optical transmittance was 90.50% in the visible range (400–700 nm) and the average bandgap was 3.98 eV. ESR spectrum of ITO film showed random oxygen vacancies which arise due to the changing crystal field effects.

ITO thin films were coated on unheated glass and Si-wafer (100) substrates by ion-assisted evaporation. The effects of post annealing, in vacuum at 250°C and 350°C for 1 h, on the structural, optical and electrical properties were studied. The structure was characterized by X-ray diffraction (XRD). The surface morphology of the films was investigated by atomic force microscopy (AFM). The optical properties were evaluated by spectrophotometer and spectroscopic ellipsometry (SE). The resistivity was measured by the four-point probes method. It was found that the increase of post-annealing temperature would improve the film crystallinity and electrical properties. The preferred orientation of ITO thin film after annealing is (222). The resistivity of the as-deposited film is found to be 5.52 × 10^-4 Ωcm and decreases to 2.11 × 10^-4 Ωcm after annealing at 350°C. The AFM image reveals that the surface roughness decreases with increasing annealing temperature. The uniqueness test based on SE analysis data has been applied for ITO modeling. This modeling indicates that the film microstructure consists of three layers including the higher-index ITO layer, the effective medium approximation (EMA) layer to represent a slightly lower optical index, and the surface roughness layer on top. The EMA thickness and its relative composition decrease with increasing annealing temperature. The extinction coefficient in the IR region increases whereas the refractive index decreases with increasing annealing temperature.

In this paper, using a cross-shaped complementary Indium Tin Oxide (ITO)-based metasurface design, the transmission of THz radiation is shown to be filtered within the 3 dB level from maximum in the frequency range of interest ($\sim$333 GHz). Various metasurface structures primarily composed of cross-shaped openings with a 400 micron unit cell size are patterned on top of 1750 micron thick fused silica substrates. They are patterned using UV lithography methods after the films were grown using DC sputtering. The fabricated structures were characterized using Terahertz Time Domain Spectroscopy (THz-TDS) measurement technique. The measured transmission agrees well with the simulation of the structure for four different samples with different geometries. These results suggest that metasurface and/or metamaterial patterns based on ITO in visibly transparent media can be utilized for filtering of frequencies in the long wavelength spectrum. These types of filters can be very useful in the near future for THz communication and security applications.

A highly sensitive surface plasmon resonance (SPR) sensor composed of a photonic crystal fiber (PCF) with the D-type structure is designed and analyzed by the full-vector finite element method (FEM). Indium tin oxide (ITO) is adopted as the plasmonic substance on account of the low cost and controllable infrared range (1500–2600 nm). By optimizing the structural parameters, the sensor shows a maximum wavelength sensitivity of 46,000 nm/RIU and average sensitivity of 13,166.67 nm/RIU for analyte refractive indexes between 1.355 and 1.385. This PCF combining a circular layout and D-type structure offers excellent sensitivity while the deposition and manufacturing complexity can be reduced. This sensor will possess an extremely expansive development space in the field of chemical analysis and environmental safety.

Indium tin oxide (ITO) thin films were prepared by radio frequency (RF) magnetron sputtering and under a quite low vacuum level of 2.3 × 10^-3Pa. The sputtering was done in an Ar and O₂ gas mixture at a temperature of 200°C. A ceramic In₂O₃:SnO₂ target (10 wt% SnO₂) was used. The microstructures of the films were investigated by a field emission scanning electron microscope (FESEM) and an X-ray diffractometer (XRD). X-ray photoelectron spectroscopy (XPS) was performed to characterize the composition of the films. ITO films with a high transparency in the visible wavelength range (80–95%) were obtained. The dependency of the electrical, optical and structural properties of ITO films on both the O₂ flow ratio (O₂/(O₂ + Ar)) and the working pressure was investigated. In the case of low working pressure (1 Pa), the more highly transparent and conducting films were produced at the lower O₂ flow ratio. High working pressure (2 Pa) gave rise to low quality, low transparency and amorphous films. Under RF sputtering at low vacuum level, the main contribution to the chamber atmosphere is due to water vapor. Oxygen originating from water vapor dissociation induced by plasma plays the same role as an oxygen or water vapor flux usually intentionally introduced in the system in order to have good quality films.

The effect of passing electric current on the electrical and optical properties of indium tin oxide (ITO) films in air has been studied. Resistivities of the ITO films deposited by direct current magnetron sputtering on glass substrates were about 10.5 × 10^-4Ωcm (group A) and 4.3 × 10^-4Ωcm (group B). A constant electric current i between 30 and 150 mA was applied to the films in air for 3 h. The results show that there is a critical current (i_cri) for each group sample. i_cri of group A is 60 mA and i_cri of group B is 90 mA. When i > i_cri, the electrical performance declines and optical transmittance increases for the electric annealed sample. However, both the electrical and optical performances may be improved for the annealed film when i ≤ i_cri. It is found that the variations in electrical and optical properties of the films strongly depend on the electric power applied to ITO films.

Indium tin oxide (ITO) nanoparticles were synthesized by co-precipitation method using ammonia as a precipitator in absence/presence of various surfactants (LABS and Triton X-100). The synthesized nanoparticles were investigated by scanning electron microscopy, resistance measurement, photoluminescence (PL) spectroscopy and X-ray diffractometry (XRD) techniques. The XRD patterns of nanoparticles were also studied by Rietveld refinement method for calculation of crystallite size, micro-strain and lattice parameter. The results indicate that by application of LABS and Triton X-100 as surfactant the particle size was increased. Two luminescence bands were observed in PL spectra of ITO nanoparticles with the excitation energy lower than their band gaps. It was found that the ratios of luminescence bands have relation with resistances and colors of ITO nanoparticles. In addition, the band structure of ITO nanoparticles was described considering the obtained results.

A sensor for detection of acetone vapors using nanostructured ITO thin film is reported. The ITO film was sputter-deposited on glass substrate using RF magnetron sputtering at 200 W RF power in argon atmosphere at 20 mTorr pressure. The film was then annealed at 450°C for 1h in air. The sensing area was kept to be 3 mm × 3 mm. Two aluminum pads of 7 mm × 4 mm size were formed using lift-off technique for electrical contacts. The crystallinity, microstructure, and acetone vapor-sensing properties were systematically investigated. The stability of the sensing films with aging and temperature variations was also investigated.

In this paper, a modified seed-mediated growth approach to produce gold nanoparticles through HAuCl₄ chemical reduction in water fabricated by growth process on indium tin oxide (ITO) was proposed. Particular attention was devoted to exploring the seeding and growth number cycle process in the formation of Au nanoparticles on the ITO surface. In agreement with the assumed analytical model, we have found that the absorbance maximum intensity ${\lambda }_{\mathrm{\text{max}}}$ depends substantially on the metal nanoparticles’ sizes, shape and density on the ITO surface. The deposited nanoparticles’ synthesized parameters were evaluated by the surface images obtained using field emission scanning electron microscopy (FE-SEM), UV-Vis spectroscopy and electrochemical measurements. The results show that the electrochemical responses of the as-prepared sample were significantly improved, in particular for the 2-cycle seeded particles followed by one-cycle growth.

In this research work the electrochemical oxidation of ortho-aminophenol (oAP) is studied using modified reduced graphene oxide/indium tin oxide (rGO/ITO) glass electrode in acetonitrile medium, tetrabutyl ammonium perchlorate (TBAP) supporting electrolyte. Cyclic voltammetry (CV) and linear-sweep voltammetry (LSV) techniques were used to study the redox behavior of oAP. The graphene oxide-initiated auto-oxidized 2-aminophenoxazine-3-one is irreversibly reduced by modified rGO/ITO glass electrode at −0.048V (versus Ag–AgCl electrode). LSV response shows that the cathodic peak current increases notably compared to that of bare rGO/ITO glass electrode and with the increasing concentration of oAP. The oxidized product of oAP was characterized by UV–Visible and FT-IR spectroscopy. The redox behavior of oAP of modified rGO/ITO glass electrode was compared with the electrochemical behavior of oAP at bare glassy carbon electrode.

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide (ITO) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

In this research an electrode-set is used to investigate via an ultra-precise method for the removal of Indium Tin Oxide (ITO) thin-film microstructure from defective display panels to conquer the low yield rate in display panel production as to from imperfect Indium Tin Oxide layer deposition is well known. This process, which involves the removal of ITO layer substructure by means of an electrochemical removal (ECMR), is of major interest to the optoelectronics semiconductor industry. In this electro machining process a high current flow and high feed rate of the display (color filter) achieves complete and efficient removal of the ITO layer. The ITO thin-film can be removed completely by a proper combination of feed rate and electric power. A small gap between the diameter cathode virtual rotation circle and the diameter virtual rotation circle also corresponds to a higher removal rate. A small anode edge radius with a small cathode edge radius effectively improves dregs discharge and is an advantage when associated with a high workpiece feed rate. This precision method for the recycling of defective display screen color filters is presented as an effective tool for use in the screen manufacturing process. The defective Indium Tin Oxide thin-film can be removed easily and cleanly in a short time. The complete removal of the ITO layer makes it possible to put these panels back into the production line for reuse with a considerable reduction of both waste and production cost.