In this study, we investigated the electrical stability and performance enhancement of In₂O₃ thin-film transistors (TFTs) through hydrogen peroxide (H₂O₂) and ultraviolet (UV) treatment under controlled temperature conditions. The In₂O₃ TFTs were fabricated using a sol-gel process, followed by H₂O₂ treatment at 40, 50, and 60℃ in combination with UV irradiation. The impact of these processing conditions on the device characteristics, including mobility (μ), threshold voltage (Vth), subthreshold swing (S/S), and on/off current ratio, was systematically analyzed. The results indicate that the 50℃ TFTs exhibited the most stable electrical performance, with minimal Vth shift under negative bias stress (NBS) conditions and optimized switching behavior. Furthermore, static inverter measurements confirmed the reliable voltage transfer characteristics (VTCs) and gain performance of the optimized In₂O₃ TFTs. These findings suggest that the proposed H₂O₂ and UV treatment technique can effectively improve the reliability and long-term stability of In₂O₃-based electronic devices, making them promising candidates for future electronic applications.

Recently, as interest in personal hygiene has increased due to the community spread of COVID-19 and variant viruses, fixed and potable UV germicidal equipment to sterilize indoor spaces and hand-held UV germicidal equipment to sterilize household items such as masks and mobile phones are continuously being developed and sold. However, the development and sales of the product are difficult because appropriate testing methods have not yet been established. In this situation, if an uncertified product is distributed in the market, it can cause serious harm to consumers. In this study, we investigate the photobiological risks and safety devices against UV exposure of UV germicidal equipment distributed domestically, and propose appropriate test methods for portable UV germicidal equipment based on the research results.

The formation of inorganic thin films in low-temperature solution processes is necessary for a wide range of commercial applications of organic electronic devices. Aluminum oxide thin films can be utilized as barrier films that prevent the deterioration of an electronic device due to moisture and oxygen in the air. In addition, they can be used as the gate insulating layers of a thin film transistor. In this study, aluminum oxide thin film were formed using two methods simultaneously, a thermal process and the DUV process, and the properties of the thin films were compared. The result of converting aluminum nitrate hydrate to aluminum oxide through a hybrid process using a thermal treatment and DUV was confirmed by XPS measurements. A film-based a-IGZO TFT was fabricated using the formed inorganic thin film as a gate insulating film to confirm its properties.

Privacy films are typically manufactured by combining black resin and transparent louver-shaped patterns. The use of black resin results in excellent light-shielding. However, black resin can reduce the transmittance of privacy films at the front viewing angle. In this study, we applied SiO₂/SiON multi-layer thin films on a privacy film to maintain transmittance at the front viewing angle and improve light-shielding at the side viewing angle. We determined the optimum combination of thicknesses of the SiO₂/SiON multi-layer stacks to increase the overall transmittance; the light shielding could be maximized at the side viewing angle.

A total internal reflection (TIR) linear lens of size 190 (W) × 5 (D) × 2.1 (H) ㎣ has a directivity of 25° and was made of a polydimethysiloxane (PDMS) silicone resin with a refractive index of 1.4 and a transmittance of 93% at 365 nm UV wavelength. A light source with a size of 190×25.5 ㎟ was fabricated by installing a TIR linear lens on a chip on board (COB) type LED module mounted with a 1.1×1.1 ㎟ size UV LED. The optical characteristics of the light source showed a maximum irradiation density of 3,840 mW/㎠ at a working distance of 5 mm and a high uniformity of 91.6% over a 150×25 ㎟ irradiation area. The thermal characteristics of the light source were measured at a supply current of 500 mA. The saturation temperature was reached after 30 min of operation, and measured to be 95℃.

Ultraviolet (UV) photodetectors are used in various industries and fields of research, including optical communication, flame sensing, missile plume detection, astronomical studies, biological sensors, and environmental research. However, general UV detectors that employ Schottky junction diodes and p^-n junctions have high fabrication cost and low quantum efficiency. In this study, we investigated the characteristics of materials used to manufacture UV photodetectors in a low-cost solution process that requires easy fabrication of flexible substrates. We fabricated p-type NiO and n-type ZnO substrates with wide band gap by the sol^-gel method and compared the characteristics of substrates prepared under different spin-coating and heat-treatment conditions.

Hole explosion behaviors were observed during drilling fine holes with laser beam on the LTCC green bar of 320 ㎛ thick after lamination of green sheets prepared by tape casting of thick film process. The incidence of these hole explosions was inversely proportional to hole sizes. The incidence of hole explosion was 20 % number of hole with the size of 60 ㎛ exploded for the UV radiation, while the explosion did not appear for hole sizes over 100 ㎛. To prevent hole explosion behavior during laser-drilling of fine holes, carbon black powder was added as an additive in the LTCC composition, which has superior thermal durability. As a consequence, hole explosion rate was suppressed to 0.8 % for the hole size of 50 ㎛ green sheet with the carbon black amount of 10 weight % and the laser power of 3 watt. Added carbon is thought to reduce the heat-affected region during laser drilling.

The amount of electrical energy has been increased with the rapid development of the industrial society. Accordingly, operating voltage of the power equipment and facility capacity are continuously increasing. Development trends of recent high-voltage electrical equipment are ultra high-voltage, large-capacity and compact. Early diagnosis of a failure of the power plant has been emerging as an important task as to supply high quality power to users. In this study, we have tried to develope an algorithm for distinguishing an arc fault signal generated in the power plant by using UV sensor.

The improvement of irradiation intensity and irradiation uniformity is essential for large area and high power UVA light source application. In this study, large number of chips bonded by micro soldering technique were driven by low current, and current limiting diodes were configured to supply constant current to parallel circuits consisting of large number of series strings. The dimension of light source module circuit board was 350 × 90 mm2 and 16,650 numbers of 385 nm flip chip LEDs were used with a configuration of 90 parallel and 185 series strings. The space between LEDs in parallel and series strings were maintained at 1.9 mm and 1.0 mm distance, respectively. The size of the flip chip was 750 × 750 μm2 were used with contact pads of 260 × 669 μm2 size, and SAC (96.5 Sn/3.0 Ag/0.5 Cu) solder was used for flip chip bonding. The fabricated light source module with 7.5 m A supply current showed temperature rise of 66℃, whereas irradiation was measured to be 300 mW/cm2. Inaddition, 0.23% variation of the constant current in each series string was demonstrated.

WO3, SiO2, and TiO2 films with hydrophilic property are deposited by rf-magnetron sputtering. Their wettability is strongly depends on the presence or absence of the oxygen plasma etching on the glass substrates. The TiO2 film of 50 nm-thick on the plasma etched glass shows a water contact angle (WCA) below 5o which means a super-hydrophilic surface. However, WCA values are gradually degraded when the films are exposed under atmosphere, especially WO3. In order to improve hydrophilic property, the degraded films can be again recovered by UV illumination for 10 sec using UV-light and the TiO2 film shows a super-hydrophilic surface about 3o.

Concern for the TOS (Transparent Oxide Semiconductor) is increasing with the recent increase in interest for flexible device. Especially MgZnO has attracted a lot of attention. MgxZn1-xO, which ZnO-based wideband-gap alloys is tuneable the band-gap ranges from 3.36 eV to 7.8 eV. In particular, the flexible substrate, the crystal structure of the amorphous as well as the surface morphology is not good. So research of MgZnO thin films growth on flexible substrate is essential. Therefore, in this study, we studied on the effects of the oxygen partial pressure on the structural and crystalline of Mg0.1Zn0.9O thin films. MgZnO thin films were deposited on PES substrate by using pulsed laser deposition. We used XRD and AFM in order to observe the structural characteristics of MgZnO thin films. UV-visible spectrophotometer was used to get the band gap and transmittance. Crystallization was done at a low oxygen partial pressure. The crystallinity of MgZnO thin films with increasing temperature was improved, Grain size and RMS of the films were increased. MgZnO thin films showed high transmittance over 80% in the visible region.

The effect of co-sputtering condition on the structural properties of Mg_xZn_1-xO thin films grown by RF magnetron co-sputtering system was investigated for manufacturing UV LED. Mg_xZn_1-xO thin films were grown with ZnO and MgO target varying RF power. Structural properties were investigated by X-ray diffraction (XRD) and Energy dispersive spectroscopy (EDS). The Mg_xZn_1-xO thin films have sufficient crystallinity on the high ZnO power. The EDS analyzed showed that the Mg content in the Mg_xZn_1-xO films decreased from 3.99 to 24.27 at.% as the RF power of ZnO target increased. The Mg content in the Mg_xZn_1-xO films could be controlled by co-sputtering power.

We use UV(ultraviolet)-O3 treatment to increase the surface area and porosity of TiO2 films in dye-sensitized solar cells (DSSCs). After the UV-O3 treatment, surface area and porosity of the TiO2 films were increased, the increased porosity lead to amount of dye loading and solar conversion efficiency was improved. Field emission scanning electron microscopy images clearly showed that the nanocrystalline porosity of films were increased by UV-O3 treatment. The Brunauer, Emmett, and Teller surface area of the TiO2 films were increased from 0.71 cm2/g to 1.31 cm2/g by using UV-O3 treatment for 20 min. Also, UV-O3 treatment of TiO2 films significantly enhanced their solar conversion efficiency. The efficiency of the films without treatment was 4.9%, and was increased to 5.6% by UV-O3 treatment for 20 min. Therefore the process enhanced the solar conversion efficiency of DSSCs, and can be used to develop high sensitivity DSSCs.

A bushing is very important because it must supply the high voltage to the power equipment. Generally, the surface of bushing is contaminated with rain, dust, salt and others. A bushing with contaminations at air are serious problem in insulation. Therefore, it is important to understand the inspection and diagnoses of the safety. The ultra-violet rays(UV) camera has attracted interest from the view point of easy judgement. In this paper, we will report on the corona discharge characteristics on bushing model with contaminations. Also, UV images of discharge in air are analyzed using prototype UV camera of Korea. These results are studied at both AC and DC voltage under a non-uniform field.