Cu₂O metal oxide was synthesized using NaBH₄ as a reducing agent in this study. The transformation of Cu composite with the pH adjustment was investigated, and the conditions for Cu₂O synthesis were analyzed. As pH of the solution was changed, the synthesized Cu composite evolved into Cu/Cu₂O and Cu/Cu₂O/CuO composites. The Cu₂O composite synthesized under conditions closest to pure Cu₂O was heat-treated at 200℃. The remaining minor Cu metal was oxidized, resulting in pure Cu₂O particles with enhanced crystallinity. The synthesized Cu₂O exhibited various morphology with particle sizes of about 160~720 nm, and the shape and size of the Cu₂O particles remained significantly unchanged after heat treatment. Surface analysis was conducted to compare the changes before and after heat treatment. No significant changes were observed, except for those attributed to water evaporation. The Cu₂O synthesized via this simple chemical reduction method can be utilized in various application fields, including catalysts, optical devices, and sensors.

Various process modifications have been used to minimize SiO₂ gate oxide aging in metal-oxide-semiconductor field-effect transistors (MOSFETs). In particular, post-metallization annealing (PMA) with a deuterium ambient can effectively eliminate both bulk traps and interface traps in the gate oxide. However, even with the use of PMA, it remains difficult to prevent high levels of radiation-induced gate oxide damage such as total ionizing dose (TID) during long-term missions. In this context, additional low-temperature heat treatment (LTHT) is proposed to recover from radiation-induced damage. Positive traps in the damaged gate oxide can be neutralized using LTHT, thereby prolonging device reliability in harsh radioactive environments.

Oxide YBCO bulk superconductors are manufactured using the melt process. Because seed crystal growth method utilizes a slow-spreading layer-by-layer reaction, a long-term heat treatment is required to manufacture a single-crystal specimen of several cm. In this study, the melt process method was applied to compensate for the shortcomings of the seed crystal growth method. The thickness of the upper and lower pellets of the YBCO bulk was molded to 40 mm, and YBCO superconductor was produced by heat treatment. The measurement results of capture magnetism was in line with the literature. This results in a relationship that the higher the growth of Y211 particle in the YBCO, the higher the superconducting properties. We analyzed the YBCO superconductor, focusing on the Y₂BaCuO₅ particle distribution.

High reliability thin film transistors are important factors for next-generation displays. The reliability of transparent a-IGZO semiconductors is being actively studied for display applications. A plasma treatment can fill the oxygen vacancies in the channel layer and the channel layer/insulating layer interface so that the device can work stably under a bias voltage. This paper studies the effect of plasma treatment on the performance of a-IGZO TFT devices. The influence of different plasma gases on the electrical parameters of device and its working reliability are reviewed. The article mentions argon, fluorine, hydrogen and several ways of processing in the atmosphere. Among these methods, F (fluorine) plasma treatment can maximize equipment reliability. It is expected that the presented results will form a basis for further research to improve the reliability of a-IGZO TFT.

In this study, a TiO₂/TiO_2-x-based resistance variable memory was fabricated using a DC/RF magnetron sputtering system and ALD. In order to analyze the effect of oxygen plasma treatment on the performance of resistance random access memory (ReRAM), the TiO₂/TiO_2-x-based ReRAM was evaluated by applying RF power to the TiO_2-x oxygen-holding layer at 30, 60, 90, 120, and 150 W, respectively. The ReRAM was fabricated, and the electrical and surface area performances were compared and analyzed. In the case of ReRAM without oxygen plasma treatment, the I-V curve had a hysteresis curve shape, but the width was very small, with a relatively high surface roughness of the oxygen-retaining layer. However, in the case of oxygen plasma treatment, the HRS/LRS ratio for the I-V curve improved as the applied RF power increased; stable improvement was also noted in the surface roughness of the oxygen-retaining layer. It was confirmed that the low voltage drive was not smooth due to charge trapping in the oxygen diffusion barrier layer owing to the high intensity ReRAM applied with an RF power of approximately 150 W.

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.

An 80 nm thick zinc aluminate thin film was deposited on a glass substrate via radio-frequency (rf) magnetron sputtering and heat treated to analyze changes in the wetting angles due to a surface modification. The thin films were modified from hydrophilic to hydrophobic by a simple thermal treatment. The surface modification from a heat treatment increased the wetting angles up to 111°, which was explained by the relationship with the excess surface area. The wetting angles of the annealed thin films decreased with increasing exposure time under ambient conditions, which was attributed to the oxygen vacancies in the films that were introduced during deposition. The annealed thin films were treated by ionized oxygen via oxygen plasma. After the oxygen plasma treatment, the decreased wetting angles were maintained at ~95° for 11 days.

A solvent free, highly concentrated silica-acryl monomer hybrid sol was synthesized using aqueous colloidal silica as a precursor. The effects of the silica particle size, type of surface treatment agent employed, and silica content on the formation of the hybrid sol were systematically studied. The optical and physical properties of the coating solution prepared using the hybrid sol were also characterized. The viscosity of the hybrid sol tended to decrease as the particle size of the silica and the molecular weight of the surface treatment agent increased. The PET substrate coated with MPTMS-Mix (mixture, 70 wt%) solution showed the highest surface hardness (6 H) and low surface roughness (Ra= 0.044 μm), which could be attributed to an increase in packing density caused by the infiltration of small particles into the pores formed between larger particles.

There is a need for the development of transparent conductive materials that are economical and environmentally friendly with exhibit low resistivity and high transmittance in the visible spectrum. In this study, the deposition rate and uniformity of Al-doped ZnO-thin films were improved by changing the Z-motion of the sputtering system. The deposition rate and the uniformity were determined to be 3.44 nm/min and 1.23%, respectively, under the 10 mm Z-motion condition. During O2 plasma treatment, the intrusion-type metal elements in the thin film were reduced, which contributed to an oxygen vacancy reduction in addition to structural stabilization. Moreover, the sheet resistance was more easily saturated.

In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. In this study, we fabricated a NO_X gas sensor by using a multi-walled carbon nanotube (MWCNT)/zinc oxide (ZnO) composite film. The fabricated MWCNT/ZnO gas sensor was then treated by a 450℃ temperature process to increase its detection sensitivity for NOx gas. We compared the detection characteristics of a ZnO film gas sensor, MWCNT film gas sensor, and the MWCNT/ZnO composited film gas sensor with and without the heat-treatment process. The fabricated gas sensors were used to detect NO_X gas at different concentrations. The gas sensor absorbed NO_X gas molecules, exhibiting increased sensitivity. The sensitivity of the gas sensor was increased by increasing the gas concentration. Additionally, while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained its sensitivity for detecting NO_X gas. Compared with ZnO, the MWCNT film gas sensor is excellent for detecting NO_X gas. From the experimental results, we confirmed the enhanced gas sensor sensing mechanism. The increased effect by electronic interaction between the MWCNT and ZnO films contributes to the improved sensor performance.

We propose a method for improving the reliability of a solar cell by applying a fluorinated surface coating to protect the cell from the outdoor environment using an atmospheric pressure plasma (APP) treatment. An APP source is operated by radio frequency (RF) power, Ar gas, and O₂gas. APP treatment can remove organic contaminants from the surface and improve other surface properties such as the surface free energy. We determined the optimal APP parameters to maximize the surface free energy by using the dyne pen test. Then we used the scratch test in order to confirm the correlation between the APP parameters and the surface properties by measuring the surface free energy and adhesive characteristics of the coating. Consequently, an increase in the surface free energy of the cover glass caused an improvement in the adhesion between the coating layer and the cover glass. After treatment, adhesion between the coating and cover glass was improved by 35%.

Inductively coupled plasma (ICP) treatment with argon and a mixture of argon and oxygen gases has been used to modify the surface of polycarbonate (PC) substrates. The results showed that the surface contact angle was inversely proportional to the plasma discharge power and that the mixed-gas plasma (gas flow 10:10 sccm, discharge power 60 W) decreased the surface contact angle as low as 18.3°, indicating a large increase in the surface hydrophilicity. In addition, SnO₂ thin films deposited on the PC substrate effectively enhanced the ICP plasma treatment, and could also enhance the usefulness of PC in the inner parts of automobiles.

The effect of NH₃ plasma treatment on device characteristics was confirmed for an optimized thin film transistor of poly-Si formed by ELA. When C-V curve was checked for MIS (metal-insulator-silicon), Dit of NH₃ plasma treated and MIS was 2.7×10¹⁰ cm^-2eV^-1. Also in the TFT device case, it was decreased to the sub-threshold slope of 0.5 V/decade, 1.9 V of threshold voltage and improved in 26 cm²V^-1S^-1 of mobility. Si-N and Si-H bonding reduced dangling bonding to each interface. When gate bias stress was applied, the threshold voltage`s shift value of NH₃ plasma treated device was 0.58 V for 1,000s, 1.14 V for 3,600s, 1.12 V for 7,200s. As we observe from this quality, electrical stability was also improved and NH3 plasma treatment was considered effective for passivation.

ZnO thin films were deposited by RF magnetron sputtering and then diffused by using an As source in the ampouletube. Also, the ZnO p-n homojunction was made by using As-doped ZnO thin films, and its properties were analyzed. After the As doping, the surface roughness increased, the crystal quality deteriorated, and the full width at half maximum was increased. The As-doped ZnO thin films showed typical p-type properties, and their resistivity was as low as 2.19×10^-3 Ωcm, probably because of the in-diffusion from an external As source and out-diffusion from the GaAs substrate. Also, the ZnO p-n junction displayed the typical rectification properties of a p-n junction. Therefore, the As diffusion method is effective for obtaining ZnO films with p-type properties.

Powder compaction technology is widely used to prepare thermal battery components. This method, however, is limited by the size, thickness, and geometry of the battery components. This limitation leads to excessive cell capacity, overweight, and higher cost of the pellets, which decreases the specific capacities and delays the activation time of thermal batteries. FeS₂ thin-film cathodes were fabricated by tape-casting technology and analyzed by SEM and EDS in this paper. The residual organic binder of the FeS₂ thin-film cathodes decreased with the temperature of the heat treatment, which improved the specific capacity because of the lower resistance. Specific capacities of the FeS₂ thin-film cathodes decreased because of the higher residual binder and the restrictive reaction of active materials with molten salts as the thickness increased. FeS₂ thin-film cathodes showed much higher specific capacity (1,212.2 As/g) than pellet cathodes (860.7 As/g) at the optimal heat-treatment temperature (230℃).

ZnO:Al thin films were deposited on glass substrate by RF magnetron sputtering followed by in situ heat treatment in the same chamber. Effects of in situ heat treatment on properties of ZnO:Al thin films were investigated in this study. As heat treatment temperature was increased, crystal quality was improved first and then it was deteriorated, surface roughness was decreased, and sheet resistance was also decreased. The decrease in sheet resistance was caused by increasing carrier concentration due to decreased surface roughness. The decrease in surface roughness resulted in increase of transmittance. Therefore, in situ heat treatment is an effective method for obtaining films with better electrical characteristics.

The Ag thin film of YBCO (yttrium barium copper oxide) CC (coated conductor) protect the YBCO layer and, at the same time, affects the electrical characteristics of the YBCO CC. Therefore, YBCO CC with the commercialization of the Ag thin film layers makes it easy to establish a process, it can lead to a variety of characteristic changes in YBCO CC. In this paper, plasma surface treatment was carried out to facilitate the deposition of the Ag thin film and the deposition process of YBCO CC. Surface roughness from the test results was increased as the time of the plasma surface treatment increased from 5 to 20 minutes. On the other hand, the surface roughness was decreased for the time of the plasma surface treatment over 20 minutes. Furthermore, after depositing, the increasing of deposit amount and reduced lifting phenomenon showed a similar tendency with the rise time of surface roughness.

We investigated and compared two methods of in-situ oxidation and chemical etching treatment (CET) to remove the boron rich layer (BRL). The BRL is generally formed during boron doping process. It has to be controlled in order not to degrade carrier lifetime and reduce electrical properties. A boron emitter is formed using BBr3 liquid source at 930℃. After that, in-situ oxidation was followed by injecting oxygen of 1,000 sccm into the furnace during ramp down step and compared with CET using a mixture of acid solution for a short time. Then, we analyzed passivation effect by depositing Al2O3. The results gave a carrier lifetime of 110.9 ㎲, an open-circuit voltage (Voc) of 635 mV at in-situ oxidation and a carrier lifetime of 188.5 ㎲, an Voc of 650 mV at CET. As a result, CET shows better properties than in-situ oxidation because of removing BRL uniformly.

To provide the clear images from the direct light on electrical board and display devices, anti glare treatment of display cover glass is needed. In this study, the effects of surface treatment temperature, concentration, and etching solution coating thickness of the gel phase on optical elements control such as gloss, haze of reflected light and transmittance, were investigated. Cover glasses were treated at different coating thickness and additive concentration. The optical properties were examined using spectrophotometer, gloss and haze meter. The surface morphology and roughness were measured by the optical microscope and Ra measuring instrument. The etching rate and surface morphologies were dramatically affected by the concentration of acid additive in the viscous gel because of re-crystallization of components in the etching solution, hydrogel formation and coagulant after coating on glass substrate. In our experimental range, cover glass which is surface-treated with various optical properties as well as the morphology uniformity was obtained; in particular, optical properties could be controlled by etching solution coating thickness of the gel phase and the concentration of additive. The gloss was depended on the surface roughness and it showed the linear relationship between optical transmittance and haze of reflected light, respectively.

The physical effects of H-plasma treatment on ZnO thin film have been studied using photoluminescence(PL) spectroscopy. Four characteristic peaks have been identified: (i) D0X peak (neutral donor-bound exciton), showing relatively small integrated intensity after H-plasma treatment, indicates that H-plasma passivates the neutral donors in ZnO at low temperatures. The rapid decrease in the integrated intensity of the peak as the temperature goes up is considered to be due to the ionization of neutral donors. (ii) H-related complex-bound exciton peak appears at the low temperatures (10 K∼80 K)after H-plasma treatment, showing the same thermal evolution as D0X peak. (iii) FX (free exciton) peak starts to show up at 60 K and grows more and more as the temperature goes up, which is considered to be related to the increase in free electron concentration in the film. (iv) violet band is intensified after H-plasma, which means more defects and impurities are generated by H-plasma process.

Glass ceramic has a high mechanical strength and low sintering temperature. So, it can beused as a thick film substrate or a high strength insulator. A series of glass ceramic samples based onMgO-Al2O3-SiO2-ZrO2 (MASZ) were prepared by melting at 1,600℃, roll-quenching and heat treatment atvarious temperatures from 900℃ to 1,400℃. Dependent on the heat treatment temperature used, glassceramics with different crystal phases were obtained. Their nucleation behavior, microstructure andmechanical properties were investigated with differential thermal analysis (DTA), X-ray diffraction (XRD),scanning electron microscopy (SEM), and Vicker`s hardness testing machine. With increasing the heattreatment temperature of MASZ samples, their hardness and toughness initially increase and then reachthe maximum points at 1,300℃, and begin to decrease at above this temperature, which is likely to bedue to the softening of glass ceramics. As the content of ZrO2 in MAS glass ceramics increases from 7.0wt.% to 13 wt.%, Vicker`s hardness and fracture toughness increase from 853 Kg/mm2 to 878 Kg/mm2and 1.6 MPa??m1/2 to 2.4 MPa??m1/2 respectively, which seems to be related with the nucleation of elongatedphases like fiber.

CIGS is one of thin film solar cell and has been studied so much, because of the possibility of low price and high efficiency. Until now, co-evaporation and sputtering were typical method to prepare CIGS absorption layer, and a few company commercialized solar cell by these method. However,non-vacuum process which has been studied for long time has not been progressed, though the merit of low price. Especially, aerosol deposition method has not been reported, because it is difficult to prepare a large quantity of various CIGS powder. In this study, CIGS powder was synthesized by mechanochemical method and CIGS absorption layer was deposited by aerosol deposition method. The thickness of the CIGS layer was controlled by the number of deposition and the surface roughness of it was affected by the amount of flow gas. And, also, I-V curve of it appeared metallic property in the case of ‘as deposition’. After heat treatment in Se-rich atmosphere, the electrical property of it changed to a semiconductor. CdS and transparent conduction layer were formed by a typical method on it for solar cell. The efficiency of cell was appeared 0.19%. Though the efficiency was low because of the disharmony in the after-process, it was conformed that CIGS solar cell could be prepared by aerosol deposition.

Electrodeionization is a hybrid separation process of electrodialysis and ion exchange to produce high purity water under electric field. This article provides a fabrication result of hole patterned metal electrode for elecrodeionization system. The hole patterns have been fabricated by nanosphere lithography (NSL). The technique utilizes the self-assembled nanospheres as lens-mask patterns and collimated laser beam source. The hole patterns have a periodic array structure. The images of hole pattern on metal electrode prepared were observed by SEM. We believe that the periodic hole patterned metal electrode structure is a useful device applicable for metal mat electrode in electrodeionization system.

This study is explore the photoelectric conversion change of dye-sensitized solar cells with surface treatment of the conductive substrate. gases of FTO surface treatment were N2, and O2. Treatment conditions of surface were gas flux from 25 sccm to 50 sccm and RF power were from 25 W to 50 W. Treatment time and pressure were fixed 5 min and 100 mtoor. The best sheet resistance and surface roughness were obtained by O2 50 sccm and 50 W and that result were 7.643 Ω/㎠ and 17.113 nm, respectively. The best efficiency result was obtained by O2 50 sccm and 50 W and that result of Voc, Jsc, FF and efficiency were 7.03 V, 14.88 mA/㎠, 63.75% and 6.67%, respectively.

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.

The optical properties of ZnO thin film, being treated by O-plasma, have been studied using Photoluminescence(PL) spectroscopy with the change of temperature from 10 K to 290 K. Two characteristic peaks were identified at 10 K:3.357 eV(DoX) and 3.324 eV(TES). The peak of DoX is believed to be due to neutral donor bound excitons where the donor is in the ground state. However, the TES(Two Electron Satellite) peak indicates the excited state of the donor(excitation energy was ~30 meV). The donor binding energy was estimated to be 44 meV, which indicates the possible presence of the neutral donor bound excitons at RT. The thermal effect including thermal broadening was identified from temperature evolution of the spectrum. Both the peak intensity and the peak energy have decreased as the temperature increases. As the temperature approaches to RT, the two peak merges into one broad peak, which is considered a combination of multiple peaks having different physical origins.

We optimize electrical and optical properties of thermal and SF6 plasma treated indium tin oxide (ITO)/Al based reflector for high-power ultraviolet (UV) light-emitting diodes (LEDs). After thermal and SF6 plasma treatments of ITO/Al reflector, the specific contact resistance decreased from 1.04×10(-3) Ω·cm2 to 9.12×10(-4) Ω·cm2, while the reflectance increased from 58% to 70% at the 365 nm wavelength. The low resistance and high reflectance of ITO/Al reflector are attributed to the reduced Schottky barrier height (SBH) between the ITO and AlGaN by large electronegativity of fluorine species and reduced interface roughness between the ITO and Al, respectively.

Recently, amorphous oxide semiconductors (AOSs) based thin-film transistors (TFTs) have received considerable attention for application in the next generation displays industry. The research trends of AOSs based TFTs investigation have focused on the high device performance. The electrical properties of the TFTs are influenced by trap density. In particular, the threshold voltage (Vth) and subthreshold swing (SS) essentially depend on the semiconductor/gate-insulator interface trap. In this article, we investigated the effects of Ar plasma-treated SiO2 insulator on the interfacial property and the device performances of amorphous indium gallium zinc oxide (a-IGZO) TFTs. We report on the improvement in interfacial characteristics between a-IGZO channel layer and gate insulator depending on Ar power in plasma process, since the change of treatment power could result in different plasma damage on the interface.

The characteristic changes in ZnO thin film according to H- and O- plasma treatments have been studied by Photoluminescence (PL) spectroscopy at room temperature. The red shift of UV peak by 20-30 meV in PL spectra after plasma treatments is identified, which indicates that there are changes in the binding energy of bound exciton and/or the movement of energy levels of lattice defects and impurities. The width of UV peak is decreased after plasma treatments, which is believed to be closely related to the crystal quality of ZnO film. The increase of UV peak intensity after H-plasma treatment is also observed, and this could mean that the radiative recombination is strengthened because the hydrogen atoms in the plasma diffuse into the film where they passivate and neutralize the defects and the impurities.

In this study, we fabricated the flexible pentacene TFTs with the polymer gate dielectric and contact printing method by using the silver nano particle ink as a source/drain material on plastic substrate. In this experiment, to lower the cross-linking temperature of the PVP gate dielectric, UV-Ozone treatment has been used and the process temperature is lowered to 90℃ and the surface is optimized by various treatment to improve device characteristics. We tried various surface treatments; O2 Plasma, hexamethyl-disilazane (HMDS) and octadecyltrichlorosilane (OTS) treatment methods of gate dielectric/semiconductor interface, which reduces trap states such as -OH group and grain boundary in order to improve the OTFTs properties. The optimized OTFT shows the device performance with field effect mobility, on/off current ratio, and the sub-threshold slope were extracted as 0.63 cm2 V-1s-1, 1.7 x 10(-6), and of 0.75 V/decade, respectively.