Ultraflat indium tin oxide films prepared by ion beam sputtering

Indium tin oxide (ITO) films with a smooth surface (root-mean-square roughness; R_rms=0.40 nm) were made using a combination of the deposition conditions in the ion beam-sputtering method. Sheet resistance was 13.8 Ω/sq for a 150-nm-thick film grown at 150 °C. Oxygen was fed into the growth chamber during film growth up to 15 nm, after which, the oxygen was turned off throughout the rest of the deposition. The surface of the films became smooth with the addition of ambient oxygen but electrical resistance increased. In films grown at 150 °C with no oxygen present, a rough surface (R_rms=2.1 nm) and low sheet resistance (14.4 Ω/sq) were observed. A flat surface (R_rms=0.5 nm) with high sheet resistance (41 Ω/sq) was obtained in the films grown with ambient oxygen throughout the film growth. Surface morphology and microstructure of the films were determined by the deposition conditions at the beginning of the growth. Therefore, fabrication of ITO films with a smooth surface and high electrical conductivity was possible by combining experimental conditions.     

Underwater Image Dehazing via Unpaired Image-to-image Translation

Underwater imaging has long been focused on dehazing and color correction to address severe degradation in the water medium. In this paper, we propose a learning-based image restoration method that uses Generative Adversarial Networks (GAN). For network generality and learning flexibility, we constituted unpaired image translation frameworks into image restoration. The proposed method utilizes multiple cyclic consistency losses that capture image characteristics and details of underwater images. To prepare unpaired images of clean and degraded scenes, we collected images from Flickr and filtered out false images using image characteristics. For validation, we extensively evaluated the proposed network on simulated and real underwater hazy images. Also, we tested our method on conventional computer vision algorithms, such as the level of edges and feature matching results.

     

Detailed assessment of mesh sensitivity for CFD simulation of coal combustion in a tangential-firing boiler

Journal of Mechanical Science and Technology - Computational fluid dynamics (CFD) has become an essential tool for optimizing the design and diagnosing the operation of a boiler. However, the...     

Study of the substrate treatment effect on initial growth of indium tin-oxide films on polymer substrate using in situ conductance measurement

Changes in the initial growth mode of ion beam sputtered indium tin oxide (ITO) films on polycarbonate (PC) substrates were investigated by an in situ measurement of electrical conductance. The PC substrates were irradiated with l keV Ar ions in an oxygen environment (ion assisted reaction: IAR), prior to the film deposition for changing the surface energy. The electrical conduction modes in ITO films were discussed in terms of the film thickness and the surface energy of PC substrates. It was found that, in the initial part of the film growth, ITO nucleation density increased with the increase of the surface energy of PC. The change of the growth mode was discussed in both viewpoints of thermodynamics and atomic kinetics theories and verified by AFM (atomic force microscope) observations. Thermal stability of ITO films was investigated to observe the effect of the growth mode change by IAR pre-treatment of polymer substrate.     

Indium-tin oxide/Si contacts with In- and Sn-diffusion barriers in polycrystalline Si thin-film transistor liquid-crystal displays

Indium and tin were used as the diffusion barrier between indium-tin oxide (ITO) and polycrystalline-silicon layers to reduce the contact resistance. The ITO/Si contacts may be adopted in thin-film transistor liquid-crystal displays (TFT-LCD) to reduce the number of fabrication steps. With In and Sn layers, contact-resistance values of 5 × 10⁻³−4×10⁻³ Ωcm² were obtained. These values were higher than those of the conventional ITO/Mo/Al/Si contacts (3×10⁻⁵−4 × 10⁻⁴ Ωcm²) but lower than the values obtained from ITO/Si contacts (about 1×10⁻² Ωcm²). The Sn was stable after annealing, but In diffused into Si and lost its function as the diffusion barrier.     

Tin-doped indium oxide (ITO) film deposition by ion beam sputtering

Indium tin oxide (ITO) thin films were deposited by ion beam sputtering. This paper aimed at the reach of high conductivity and high transmittance simultaneously at relatively low substrate temperature. In order to reach the objects, the influences of substrate temperature, ion beam energy, and oxygen gas flowing rate on the properties of deposited ITO films were investigated. Resistivity showed the lowest value of 1.5×10⁻⁴ Ω cm on the films deposited by 1.3 keV Ar ions at 100°C. The microstructure of the films was sub-grain (domain) structure. The ITO films have above 80% of transmittance in the visible wavelength including that of the glass substrate.     

Influence of ITO surface modification on the growth of CdS and on the performance of CdS/CdTe solar cells

We treated the surface of indium–tin oxide (ITO) substrates in two ways, (i) coating of thin insulating ITO layer or (ii) irradiation of the surface with accelerated ions, and investigated the change in sheet resistance (R_sh) and the water-contact angle (WCA). R_sh increased with the thickness of the insulating ITO layer or with the ion dose. WCA dropped as a result of the surface treatment to <15°. The microstructure, the surface morphology, the optical transmittance, and the stoichiometry of CdS improved with the surface treatment. CdS/CdTe solar cells showed a better performance as a result of ITO surface treatment.     

Channel invariant online visibility enhancement for visual SLAM in a turbid environment

This paper presents a real‐time and channel‐invariant visibility enhancement algorithm using a hybrid image enhancement approach. The proposed method is initially motivated by an underwater visual simultaneous localization and mapping (SLAM) failure in a turbid medium. The environments studied contain various particles and are dominated by a different image degradation model. Targeting image enhancement for degraded images but not being limited to it, the proposed method provides a highly effective solution for both color and gray images with substantial improvement in the process time compared to conventional methods. The proposed method introduces a hybrid scheme of two image enhancement modules: a model‐based (extensive) enhancement and a model‐free (immediate) enhancement. The proposed method is validated by using simulated synthetic color images and real‐world color and grayscale underwater images. Real‐world validation is performed in various environments such as hazy indoor, smoky indoor, and underwater. Using the ground truth trajectory or clear images acquired from the same area but without turbidity, we evaluate the proposed visibility enhancement and camera registration improvement for a feature based (ORB‐SLAM2), a direct (LSD‐SLAM), and a visual underwater SLAM application.     

Automatic wall slant angle map generation using 3D point clouds

Recently, quantitative and repetitive inspections of the old urban area were conducted because many structures exceed their designed lifetime. The health of a building can be validated from the condition of the outer wall, while the slant angle of the wall widely serves as an indicator of urban regeneration projects. Mostly, the inspector directly measures the inclination of the wall or partially uses 3D point measurements using a static light detection and ranging (LiDAR). These approaches are costly, time-consuming, and only limited space can be measured. Therefore, we propose a mobile mapping system and automatic slant map generation algorithm, configured to capture urban environments online. Additionally, we use the LiDAR-inertial mapping algorithm to construct raw point clouds with gravity information. The proposed method extracts walls from raw point clouds and measures the slant angle of walls accurately. The generated slant angle map is evaluated in indoor and outdoor environments, and the accuracy is compared with real tiltmeter measurements.