e investigated the effects of post-annealing in vacuum, nitrogen, and hydrogen atmospheres on the structural, electrical, and optical properties of 600 nm thick Al-doped ZnO (ZnO:Al) thin films deposited by RF magnetron sputtering at room temperature. Post-annealing in hydrogen atmosphere at 400℃ for 1 hour showed the most significant improvement in electrical properties. Resistivity decreased from 9.11×10⁻³ to 1.4×10⁻³ Ω·cm, electron mobility increased from 4.11 to 18.23 cm²/V·s, and electron carrier concentration increased from 1.63×10²⁰ to 4.85×10²⁰ cm⁻³. In contrast, post-annealing in vacuum and nitrogen atmospheres resulted in degraded electrical properties due to oxygen and nitrogen chemisorption at grain boundaries. The enhancement in hydrogen-annealed films was attributed to the formation of additional oxygen vacancies and desorption of adsorbed oxygen species from grain boundaries. All films maintained excellent optical transparency of 80-90% in the visible range. The optical bandgap exhibited a blue-shift from 3.365 eV to 3.624 eV due to the Burstein-Moss effect induced by the increased electron carrier concentration. These results confirmed that hydrogen atmosphere post-annealing is the most effective method for enhancing the electrical conductivity of ZnO:Al thin films while maintaining high optical transparency.

This study investigates the post-thermal treatment effects on the efficiency of silicon heterojunction solar cells, specifically examining the influence of annealing on p-type microcrystalline silicon oxide and ITO thin films. By assessing changes in carrier concentration, mobility, resistivity, transmittance, and optical bandgap, we identified conditions that optimize these properties. Results reveal that appropriate annealing significantly enhances the fill factor and current density, leading to a notable improvement in overall solar cell efficiency. This research advances our understanding of thermal processing in siliconbased photovoltaics and provides valuable insights into the optimization of production techniques to maximize the performance of solar cells.

The advantage of OTFT technology is that large-area circuits can be manufactured on flexible substrates using a lowcost solution process such as inkjet printing. Compared to silicon-based inorganic semiconductor processes, the process temperature is lower and the process time is shorter, so it can be widely applied to fields that do not require high electron mobility. Materials that have utility as electrode materials include carbon that can be solution-processed, transparent carbon thin films, and metallic nanoparticles, etc. are being studied. Recently, a technology has been developed to facilitate charge injection by coating the surface of the Al electrode with solution-processable titanium oxide (TiOx), which can greatly improve the performance of OTFT. In order to commercialize OTFT technology, an appropriate method is to use a complementary circuit with excellent reliability and stability. For this, insulators and channel semiconductors using organic materials must have stability in the air. In this study, carbon-doped Mo (MoC) thin films were fabricated with different graphite target power densities via unbalanced magnetron sputtering (UBM). The influence of graphite target power density on the structural, surface area, physical, and electrical properties of MoC films was investigated. MoC thin films deposited by the unbalanced magnetron sputtering method exhibited a smooth and uniform surface. However, as the graphite target power density increased, the rms surface roughness of the MoC film increased, and the hardness and elastic modulus of the MoC thin film increased. Additionally, as the graphite target power density increased, the resistivity value of the MoC film increased. In the performance of an organic thin film transistor using a MoC gate electrode, the carrier mobility, threshold voltage, and drain current on/off ratio (I_on/I_off) showed 0.15 cm²/V·s, -5.6 V, and 7.5×10⁴, respectively.

Nickel oxide is a nonstoichiometric transparent conductive oxide with p-type conductivity, a wide-band energy gap of 3.4~4.0 eV, and excellent chemical stability, making it a very important candidate as a material for bipolar devices.P-type conductivity in Transparent Conductive Oxides (TCO) is controlled by the oxygen vacancy concentration. During the TCO film deposition process, additional oxygen diffusing into the NiO structure causes the formation of Ni 3p ions and Ni vacancies. This eventually affects the hole concentration of the p-type oxide thin film. In this work, the surface morphology and the electrical characteristics were confirmed in accordance with the annealing atmosphere of the nickel oxide thin film.

We investigated the properties of vanadium oxide (VOx) buffer layers deposited by a dual RF magnetron sputtering method under various target powers for inverted organic solar cells (IOSCs). Sputter fabricatged VOx thin films exhibited higher crystallinity with the increase of target power, resulting in a uniform and large grain size. The electrical properties of VOx films are improved with the increase of target power because of the increase of V content. In the results, the performance of IOSCs critically depended on the target power during the film growth because the crystalllinity of the VOx film affects the carrier mobility of the VOx film.

Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

The quench voltage of the second-generation superconducting wire is affected by the resistivity characteristics of the stabilization layer. The specific resistance of the stabilization layer can be changed by the deposition process using RF magnetron sputtering. In this paper, a thin film made of a homogeneous material (Ag) and a dissimilar material (Cu) was deposited on the stabilization layer of the second-generation superconducting wire through RF magnetron sputtering. We found that the specific resistance was reduced by increasing the thickness of the stabilization layer. The reduction in the resistivity of the stabilization layer led to a decrease in the quench voltage of the second-generation superconducting wire. We suggest that various characteristic changes of the second-generation superconducting wire can be expected through the successful change in the resistivity of the stabilization layer of the proposed deposition process.

AGZO thin films were deposited on glass substrates using RF magnetron sputtering system under Ar flow rates, and their structural, electrical, and optical properties were analyzed systematically. As a result of the XRD pattern, the peak of the (002) (2θ≈33.7˚) orientation was observed, and it was found to have a hexagonal wurtzite structure. The sheet resistance of Ar 5 sccm was 3.073×10² Ω/sq and showed the best electrical properties because of the improvement of mobility due to the increase of the grain size and the variation of RMS roughness. In addition, the average transmittance was more than 90% for all samples, which demonstrated good optical properties. It is expected that the TCO characteristics can be improved by controlling Ar flow rates, and this will increase the efficiency of photoelectronic devices such as OLED and solar cells.

In the case of ZnO:Al thin films, it is the best material that can replace ITO that is mainly used as a transparent electrode in electronic devices such as solar cells and flat-panel displays. In this study, ZnO:Al films were fabricated by using the RF dual magnetron sputtering method at various substrate temperatures. As the substrate temperature increased, the crystallinity of the ZnO:Al thin films was improved, and the electrical conductivity and electrical properties of the thin film improved owing to the increase in grain size. In addition, the surface roughness of the ZnO:Al thin films increased due to changes in the surface and density of the thin films. Moreover, the substrate temperature increased the density of thin films and improved their transmittance. To be applied to solar cells and other several electronic devices in the future, the hardness and adhesion properties of the thin film improve as the substrate temperature increases.

Using facing target magnetron sputtering (FTMS) with a graphite target source, carbon nitride thin films were deposited on silicon and glass substrates at different substrate temperatures to confirm the tribological, electrical, and structural properties of thin films. The substrate temperatures were room temperature, 150℃, and 300℃. The tribology and electrical properties of the carbon nitride thin films were measured as the substrate temperature increased, and a study on the relation between these results and structural properties was conducted. The results show that the increase in the substrate temperature during the fabrication of the carbon nitride thin films increased the hardness and elastic modulus values, the critical load value was increased, and the residual stress value was reduced. Moreover, the increase in the substrate temperature during thin-film deposition was attributed to the improvement in the electrical properties of carbon nitride thin film.

In this study, ZnO:Ga thin films were fabricated on a glass substrate using various Ar flows by an RF magnetron sputter system at room temperature. The dependencies of Ar flow on different properties were investigated. An appropriate control over the Ar flow led to the formation of a high-quality thin film. The ZnO:Ga films were formed as a hexagonal wurtzite structure with high (002) preferential orientation. The films exhibited a typical columnar microstructure and a smooth top face. The average transmittance was 85~89% within the visible area. By decreasing the Ar flow, the sheet resistance was decreased due to an increase in the grain size and a decrease in the root mean square roughness. The lowest sheet resistance of 86 Ω/□ was obtained at room temperature for the 40 sccm Ar flow.

All-solid-state thin-film lithium-ion batteries are important in the development of next-generation energy storage devices with high energy density. However, thin-film batteries have many challenges in their manufacturing procedure. This is because there are many factors, such as substrate selection, to consider when producing the thin film multilayer structure. In this study, we compare the fabrication and performance of all-solid-state thin-film lithium-ion batteries with a LiNi_0.5Mn_1.5O₄ cathode/LiPON solid electrolyte/ Li₄Ti₅O₁₂ anode structure using stainless steel and Si substrates with different surface roughness. We demonstrate that the smoother the surface of the substrate, the thinner the thickness of the all-solid-state thin-film lithium-ion battery that can be made, and as a result, the corresponding electrochemical characteristics can be improved.

Raman spectra of a-C:H thin films deposited with an unbalanced magnetron sputtering system showed that the G peak shifted to a higher wavenumber as the target power density increased and ID/IG ratio increased from 0.902 to 1.012. Moreover, the transmittance of a-C:H films fabricated at 60 nm tended to decrease with increasing target power density; at 550 nm in the visible light region, the transmittance decreased from 69% to 58%. The rms surface roughness values of the a-C:H thin films decreased with increasing target power density, and varied from 1.11 nm to 0.71 nm. In order to achieve efficient light trapping, the light scattering at the rough interface must be enhanced. Consequently, the surface roughness of the thin film will decrease with the target power density. Further, the refractive index and reflectivity of the a-C:H thin films increased with increasing target power density; however, the Brewster angle decreased with the target power density. Hence, dye-sensitized solar cells using an a-C:H antireflective coating increased the CE, VOC, and JSC by approximately 8.6%, 5.5%, and 4.5%, respectively.

TiN thin films were fabricated using an unbalanced magnetron sputtering (UBMS) system, and their structure and surface characteristics as well as their optical and tribological properties were evaluated. The hardness, elastic modulus, adhesive force, surface roughness, and transmittance of the Ti thin films fabricated using the UBMS system were 11.5 GPa, 103 GPa, 27.5 N, 2.45 nm and 20%, respectively. The TiN films prepared with various proportions of nitrogen as the reaction gas exhibited maximum values for the hardness, elastic modulus, critical load, RMS roughness and transmittance of approximately 19.2 GPa, 182 GPa, 27.3 N, 0.98 nm, and 85%, respectively. Moreover, the TiN thin film fabricated under the condition of 30 sccm nitrogen gas showed the optimal physical properties. In summary, the TiN thin films fabricated using the UBMS system exhibited excellent hardness, elastic modulus, adhesion, and smooth surface in addition to good hydrophilic properties.

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.

We investigated the tribological properties of amorphous carbon (a-C) films deposited with CrC interlayers of various thicknesses as the adhesive layer. A-C and CrC thin films were deposited using the unbalanced magnetron (UBM) sputtering method with graphite and chromium as the targets. CrC films as the interlayer were fabricated under a-C films, and various structural, surface, and tribological properties of a-C films deposited with various CrC interlayer thicknesses were investigated. With various CrC interlayer thicknesses under a-C films, the tribological properties of CrC/a-C films were improved; the increased film thickness exhibited a maximum high hardness of over 27.5 GPa, high elastic modulus of over 242 GPa, critical load of 31 N, residual stress of 1.85 GPa, and a smooth surface below 0.09 nm at the condition of 30-nm CrC thickness.

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.

Various Ni-doped carbon (C：Ni) thin films were fabricated using different Ni target power densities by unbalanced magnetron sputtering (UBM). The effects of target power density on the structural, physical, surface, and electrical properties of C：Ni films were investigated. The UBM C：Ni thin films exhibited uniformly smooth surfaces. The rms surface roughness and friction coefficient values of the C：Ni films decreased with the increase in target power density. The physical properties of the films such as hardness and elastic moduli increased while their electrical properties such as resistivity decreased with the increase in the target power density. These results show that an increase of the power density leads to an increase in the proportion of Ni and nanocrystallization of the amorphous carbon film; this contributes to the changes observed in the physical and electrical characteristics.

Ga-doped ZnO (GZO) films were deposited by an RF magnetron sputtering method on glass substrates using ZnO as a target containing 5 wt% Ga₂O₃ powder (for Ga doping). The structural, electrical, and optical properties of the GZO thin films were investigated as a function of the substrate temperatures. The deposition rate decreased with increasing substrate temperatures from room temperature to 350℃. The films showed typical orientation with the c-axis vertical to the glass substrates and the grain size increased up to a substrate temperature of 300℃ but decreased beyond 350℃. The resistivity of GZO thin films deposited at the substrate temperature of 300℃ was 7×10^-4 Ωcm, and it showed a dependence on the carrier concentration and mobility. The optical transmittances of the films with thickness of 3,000 Å were above 80% in the visible region, regardless of the substrate temperatures.

TiN (titanium nitride) films were prepared using the RF magnetron sputtering technique. The films were deposited by pure N₂ plasma sputtering. Their mechanical properties, such as nano-indentation hardness, friction coefficient, and surface wettability, have been investigated. X-ray diffraction (XRD) studies revealed that the orientation of TiN_X films changed towards the (111) orientation with decreasing working pressure due to a strong compressive stress during deposition. The strongest TiN (111) orientation was found when the film was deposited at a working pressure of 1 Pa. This film showed the largest hardness (16 GPa) and smallest friction coefficient (0.17) among the studied samples. Moreover, this film was found to be accompanied by a water-repellent surface with water contact angle more than 100°.

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.

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.

Mo doped carbon (C:Mo) thin films were fabricated with various Mo target power densities by unbalanced magnetron sputtering (UBM). The effects of target power density on the surface, structural, and electrical properties of C:Mo films were investigated. UBM sputtered C:Mo thin films exhibited smooth and uniform surfaces. However, the rms surface roughness of C:Mo films were increased with the increase of target power density. Also, the resistivity value of C:Mo film as electrical properties was decreased with the increase of target power density. From the performance of organic thin filml transistor using conductive C:Mo gate electrode, the carrier mobility, threshold voltage, and on/off ratio of drain current (Ion/Ioff) showed 0.16 cm²/V·s, -6.0 V, and 7.7×10⁴, respectively.

We investigated the characterizations of carbon films fabricated by dual magnetron sputtering under various film thickness for the electrodes in TCO-less DSSC (dye-sensitized solar cells). Carbon films prepared at various conditions were exhibited smooth and uniform surfaces without defects. Also, the rms surface roughness of carbon films was decreased from 2.25 nm to 1.0 nm with the increase of film thickness. The sheet resistance as the electrical properties are improved from 11.2×10^-3 to 2.28×10^-3 with the increase of film thickness. In the results, the performance of TCO-less DSSC critically depended on the film thickness of working electrodes, indicating the conductivity of carbon films.

Prevailing dissemination of machine tools and cutting technology have caused drastic developments of high speed dry machining with work materials of high hardness, and demands on the high-hardness-materials with high efficiency have become increasingly important in terms of productivity, cost reduction, as well as environment-friendly issue. Addition of Si to TiAlN has been known to form nano-composite coating with higher hardness of over 30 GPa and oxidation temperature over 1,000℃. However, it is not easy to add Si to TiAlN by using conventional PVD technologies. Therefore, Ti-Al-Si-N have been prepared by hybrid process of PVD with multiple target sources or PVD combined with PECVD of Si source gas. In this study, a single composite target of Ti-Al-Si was prepared by powder metallurgy of MA (mechanical alloying) and SPS (spark plasma sintering). Properties of he resulting alloying targets were examined. They revealed a microstructure with micro-sized grain of about 1~5 ㎛, and all the elements were distributed homogeneously in the alloying target. Hardness of the Ti-Al-Si-N target was about 1,127 Hv. Thin films of Ti-Al-Si-N were prepared by unbalanced magnetron sputtering method by using the home-made Ti-Al-Si alloying target. Composition of the resulting thin film of Ti-Al-Si-N was almost the same with that of the target. The thin film of Ti-Al-Si-N showed a hardness of 35 GPa and friction coefficient of 0.66.

This study examined the malfunction mode of the HCMOS IC under narrow-band high-power electromagnetic wave. Magnetron is used to a narrow-band electromagnetic source. MFR (malfunction failure rate) was measured to investigate the HCMOS IC. In addition, we measured the resistance between specific pins of ICs, which are exposed and not exposed to the electromagnetic wave, respectively. As a test result of measurement, malfunction mode is shown in three steps. Flicker mode causing a flicker in LED connected to output pin of IC is dominant in more than 7.96 kV/m electric field. Self-reset mode causing a voltage drop to the input and output of IC during electromagnetic wave radiation is dominant in more than 9.1 kV/m electric field. Power-reset mode making a IC remained malfunction after electromagnetic radiation is dominant in more than 20.89 kV/m. As a measurement result of pin-to-pin resistance of IC, the differences between IC exposed to electromagnetic wave and normal IC were minor. However, the five in two hundred IC show a relatively low resistance. This is considered to be the result of the breakdown of pn junction when latch-up in CMOS occurred. Based on the results, the susceptibility of HCMOS IC can be applied to a basic database to IC protection and impact analysis of narrow-band high-power electromagnetic waves.

Titanium oxide (TiO2) thin films were fabricated by unbalanced magnetron (UBM) sputtering. The fabricated TiO2 films were treated by oxygen plasma under various RF powers. We investigated the characteristics of oxygen plasma treatment on the surface, structural, and physical properties of TiO2 films prepared at various plasma treatment RF powers. UBM sputtered TiO2 films exhibited higher contact angle value, smooth surface, and amorphous structure. However, the rms surface roughness TiO2 films were rough, and the contact angle value was decreased with the increase of the plasma treatment RF power Also, the hardness value of TiO2 film as physical properties was slightly increased with the increase of the plasma treatment RF power. In the results, the performance of TiO2 films for self cleaning critically depended on the with the plasma treatment RF power.

We investigated the characterizations of carbon films fabricated by dual magnetron sputtering under various RF powers for the improvement of physical properties in carbon fiber (CF). All sputtered carbon films exhibited amorphous structure, regardless of RF powers, resulting in uniform and smooth surfaces. The hardness and elastic modulus are increased with the increase of RF power, and the adhesion and friction properties of carbon films were improved with the increase of RF power. In the results, The increase of RF power in the sputtering method improved tribological properties of the carbon films, and these attributes can be expected to improve the physical properties of the carbon fiber reinforcement plastics.

We have studied structural, optical and electrical properties of In-Ga-doped ZnO (IGZO) thin films. The IGZO thin films were deposited on the corning 1737 glass by RF magnetron sputtering method. The RF power in sputtering process was varied as 30, 50, 70, and 90 W respectively. All of the IGZO thin films transmittance in the visible range (400 nm ~ 800 nm) was above 83%. XRD analysis showed the IGZO thin films amorphous structure of the thin films without any peak. And also IGZO thin film have low resistivity (1.99×10-3 Ωcm), high carrier concentration (6.4×1020 cm-3), and mobility (10.3 cm2V-1s-1). By the studies we found that IGZO transparent thin film can be used as optoelectronic material and introduced application possibility for future electronic devices.

The characterizations of zinc oxide (ZnO) buffer layers grown by unbalanced magnetron (UBM) sputtering under various substrate temperatures for inverted organic solar cells (IOSCs) were investigated. UBM sputter grown ZnO films exhibited higher crystallinity with increasing the substrate temperature, resulting in uniform and large grain size. Also, the electrical properties of ZnO films are improved with increasing substrate temperature. In the results, the performance of IOSCs critically depended on the substrate temperature during the film growth because the crystalllinity of the ZnO film affect the carrier mobility of the ZnO film.