TBP (tertiarybutylphosphine), a relatively new material for phosphorus, has been studied with EDMIn (ethyldimethylindium) as an indium source for the growth of InP by MOVPE (metalorganic vapor phase epitaxy). Mirror smooth and good crystalline InP layers were obtained at 500-600℃ with the TBP/EDMIn molar ratio as low as 21. The deposited InP layers are all n-type with the electron concentration in the range of (5-10)×10(16) cm-3, which is a lot higher than those from PH3. This high concentration is due presumably to the high concentration of donor impurities in TBP. And it has been found that the formation of adduct occurs between EDMIn and TBP at room temperature when the partial pressure of EDMIn in the reactant mixture is above 1×10(-2) Torr. The high concentration of impurities in TBP and the adduct formation between EDMIn and TBP are major obstacles in replacing PH3 and TMIn for the growth of device quality InP layers.

The morphology of etch pits in commercial 4H-SiC epi-wafer were investigated by molten-KOH etching. The etching process was optimized in 525~570℃ at 2~10 min and the novel type of etch pits was revealed. This type of etch pits have been considered as TED (threading edge dislocation) II, its origin and nature, however, are not reported yet. In this work, the morphology and evolution of etch pits during epitaxial growth were analyzed and the different behavior between TED and TEDII was discussed.

A linear spring model, where the interactions among atoms are assumed to be isotropic and elastic, is employed for the study of non-polar optical phonon scattering in the valence band of alloy semiconductors. The force equations of n atoms are used in the spring model for the consideration of the random distribution of constituent atoms in an alloy semiconductor. When the number of atoms in a unit cell is assumed to be two based on the experimental result, the optical deformation potent is valid for compound semiconductors as well as alloy semiconductors.

In this study, the surface modification for a silicon(Si) mold using CHF3 inductively coupled plasma(ICP). The conditions under that plasma was treated a input ICP power 600 W, an operating gas pressure of 10 mTorr and plasma exposure time of 30 sec. The Si mold surface became hydrophobic after plasma treatment in order to CF(x)(X= 1,2,3) polymer. However, as the de-molding process repeated, it was investigated that the contact angle of Si surface was decreased. So, we attempted to investigate the degradation mechanism of the accurate pattern transfer with increasing the count of the de-molding process using scanning electron microscope (SEM), contact angle, and x-ray photoelectron spectroscopy (XPS) analysis of Si mold surface.

This paper was carried out design of 1,700 V Base Resistance Thyristor for fabrication. We decided conventional BRT (base resistance thyristor) device and Trench Gate type one for design. we carried out device and process simulation with T-CAD tools. and then, we have extracted optimal device and process parameters for fabrication. we have analysis electrical characteristics after simulations. As results, we obtained 2,000 V breakdown voltage and 3.0 V Vce,sat. At the same time, we carried out field ring simulation for obtaining high voltage.

In this study, SiC single-crystal ingots were prepared on two seed crystals with different doping level by using the physical vapor transport (PVT) technique; then, SiC crystal wafers sliced from the grown SiC ingot were systematically investigated to find the effect of seed doping level on the doping concentration and crystal quality of the SiC. To exclude extra effects induced by adjustment of the process parameters, we simultaneously grew the SiC crystals on two seed crystals with different level, which were fabricated from previous two SiC crystal ingots.

1 mol% Li2O excess 0.9(Na0.52K0.48)NbO3-0.1LiTaO3 lead-free piezoelectric multilayer ceramic actuators were investigated to determine their aging properties. To reduce the thermal aging behavior, we applied a rectified unipolar electric field of 5 kV/mm to the specimen to accelerate the electric aging behavior. By employing a rectified unipolar electric field for the piezoelectric actuators, we could remove undesirable heating from the relaxation current in the motion of the ferroelectric domain. To accelerate the aging test, the applied electric fields had a frequency of 900 Hz. To have enough time for charging and discharging, we employed an accurate time constant to design the equivalent circuit model for the aging tester. To extract exact aging behavior, we measured the pseudo-piezoelectric coefficient before and after the aging process. We also measured the electro-mechanical coupling coefficient, the frequency-dependent dielectric permittivity, and the impedance to compare with fresh and aged specimen.

When the high voltage motor fails in power plants, there will be an occurrence where the generator`s output would be reduced or the generators would trip. Despite of these effects, the causes of deterioration of the high voltage motor is very seldom investigated. In this paper, the collected data which tested in the field over 10 years have been treated statistically, and analyzed to correlate the insulation deterioration of high voltage motor and installation environment, number of start/stop, and service life. Moreover, the proper period of insulation test is developed to map out maintenance strategy and reduce maintenance costs.

An optical lens is usually produced in the manner of high temperature compression molding with tungsten carbide alloy molding cores, it is necessary to develop and study technology for super-precision processing of molding cores and coating the core surface. As main methods used in surface improvement technologies using thin film, DLC present high hardness, chemical stability, and outstanding durability of abrasion to be extensively applied in various industrial fields. In this study, the effect of DLC coating of a thin film by means of the FVAS (filtered vacuum arc source) analyzed the characteristics of thin film. Surface roughness before and after DLC coating was measured and the result showed that the surface roughness was improved after coating as compared to before coating. In conclusion, it was observed that DLC coating of the ultra hard alloy core surface for molding had an effect on improving the surface roughness and shape of the core surface. It is considered that this will have an effect on improving abrasion resistance and the service life of the core surface.

We have proposed an optical thin film and micro lens to improve the luminance of organic light emitting device. The first method, optical thin film was calculated refractive index of dielectric layer material that was modulated refractive index of organic material, ITO (indium tin oxide)and glass. The second method, microlens was applied with lenses on the organic device. Optical thin films were designed with Macleod Simulator and Micro Lenses were calculated by FDTD (finite-difference time-domain) solution. The structure of thin film was designed in organic material/ITO/dielectric layer/glass. The lenses size, height and distance were 5 ㎛, 1 ㎛, 1 ㎛, respectively. The material of micro lenses used silicon dioxide. Result, The highest luminance of OLED which applied with microlens was 11,185 cd/m2, when approval voltage was 14.5 V, applied thin film was 5,857 cd/m2. The device efficiency applying microlens increased 3 times than the device which does not apply microlens.

A Xe plasma flat lamp, which has been noticed as a new eco-friendly LCD (liquid crystal display) backlight, requires the improvement of the luminance and the luminous efficiency although it has several advantages. To improve the performance of a lamp, it is necessary to understand the effects of discharge variables on the luminous characteristics of the lamp. Since it is difficult to diagnose a lamp discharge experimentally, the numerical analysis can be used instead. In this study, the luminous characteristics of a planar type Xe plasma flat lamp were analyzed with the variation of an input voltage and a pulse frequency. The numerical analysis of a lamp discharge was then performed using a RCT (relaxation continuum) model and a LFA (local field approximation) model. The comparison with the experimental results showed that the RCT model is valid for the numerical analysis of the flat lamp. The numerical analysis also showed that the modifications of a high frequency component and a voltage falling rate in the input voltage waveform could improve the luminous characteristics of the lamp.

This research shows the electrical characteristic using excellent epoxy nano-composite of MgO 5.0 wt% and SiO2 0.4 wt% in mechanical strength test depending on nano-additive. First of all, volume resistance depending on nano-additive and temperature using high resistance meter (HP. 4329A) by increasing 10, 100, 1,000 V of applying voltage was measured. Moreover, temperature range of 25~120℃ with virgin sample was tested using TO-9B oven by Ando Company. The result showed that virgin and the samples added with MgO and SiO2 had similar value of volume resistance in low temperature and low electric field region and reduced with slow slope. The nano-composite`s volume resistance of sample added with MgO and SiO2 had higher value than virgin sample`s volume resistance in high temperature region more than 80℃. Moreover, the slope has steeply reduced. The volume resistance of sample added with MgO 5.0 wt% was 8.38×10(13) Ω·cm and it was 6.8 times more than virgin sample in high temperature at 120℃. The insulation characteristics were constant although filler has changed in low temperature region. But, in high temperature region, the value of volume resistance of sample with MgO 5.0 wt% was 7.6 times more than the virgin sample`s volume resistance.

ZnO nanostructures were developed on a Si (100) substrate from powder mixture of ZnO and 5 mol% Pd (ZP-5) as reactants by × sccm oxygen pressures(x= 0, 10, 20, 40). DTA (differential thermal analysis) result shows the Pd(5 mol%)+ZnO mixtured powder(PZ-5) is easily evaporated than pure ZnO powder. The PZ-5 mixtured powder was characterized by DTA to determine the thermal decomposition which was found to be at 800℃, 1,100℃. Weight loss(%) and ICP (inductively coupled plasma) analysis reveal that Zn vaporization is decreased by increased oxygen pressures from the PZ-5 at 1,100℃ for 30 mins. Needle-like ZnO nanostructures array developed from 10 sccm oxygen pressure, was well aligned vertically on the Si substrate at 1,100℃ for 30 mins. The lengths of the Needle-like ZnO nanostructures is about 2 μm with diameters of about 65 nm. The developed ZnO nanostructures exhibited growth direction along [001] with defect-free high crystallinity. It is considered that Zn vaporization is responsible for the growth of Needle-like ZnO nanostructures by controlling the oxygen pressures. The photoluminescence spectra of ZnO nanostructures exhibited stronger 376.7 nm NBE (near band-edge emission) peak and 529.3 nm DLE (deep level energy) peak.

Two kind of Ag-pastes were prepared for integrating the bulk Si solar cell. One is the Ag-paste with Pb-based glass frit and the other is that with Bi-based glass frit. The pastes were the mixture of 84 wt% Ag, 2 wt% glass frit, 11 wt% solvent of buthyl cabitol acetate, and 2 wt% additives. After fabricating the Ag-pastes, they was coated on a SiN(x)/n+/p- stacks of a commercial mono-Si solar cell. The solar cell efficiency was 17.6% in the case of the Pb-based Ag-paste. However that was 16.2% in the solar cell integrated with the Bi-based Ag-paste. The lower performance in Bi-based Ag-paste was caused by the higher series resistance and the lower shunt resistance in comparison with the Pb-based Ag-paste.

Nano-fibers of the Li[Ni1/3Co1/3Mn1/3]O2 electrode were synthesized from a metal oxide precursor using the electrospun method. The XRD patterns of all prepared powders showed a hexagonal α- NaFeO2 structure (space group: R-3 m, 166). Scanning electron microscopy showed that all the synthesized samples were comprised of nanofibers with a size of 100~800 nm. Among the samples tested, the calcined Li[Ni1/3Co1/3Mn1/3]O2 nanowires in oxygen heating atmosphere showed a high charge and discharge capacity of 239.22 and 172.81 mAhg-1 at the 1st cycle, respectively. In addition, the charge transfer resistance was also improved significantly compared to the other samples.