• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1990.10a
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• pp.39-44
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• 1990

Polycrystalline CdS films were grown on glass substrate with conducting indium tin oxide(ITO) by electrodeposition. The average size of the plate-shape grains o the CdS films was from 0.3um to 0.05um, and the adhesion to ITO was excellent. The optical band gap of the electrodeposited CdS films was in the range from 2.51eV to 2.68 eV. The optical transmittance was 80% and the electrical resistivity varied from 10$^3$ to 10$\^$5/$\Omega$-cm depending on the deposition condition.

• Current Optics and Photonics
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• v.7 no.5
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• pp.569-573
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• 2023

We utilized terahertz time-domain spectroscopy (THz-TDS) to measure the thickness and electrical properties of nickel-chromium (Ni-Cr) films. This technique not only aligns well with traditional methods, such as haze-meter and transmission-densitometer measurements, but it also reveals the electrical properties and thickness of films down to a few tens of nanometers. The complex conductivity of the Ni-Cr thin films was extracted using the Tinkham formula. The experimental values closely aligned with the Drude model, indicating the reliability of our Ni-Cr film's electrical and optical constants. The thickness of Ni-Cr was estimated using the complex conductivity. These findings emphasize the potential of THz-TDS in quality control of metallic nanofilms, pointing toward an efficient and nondestructive test (NDT) for such analyses.

• Current Optics and Photonics
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• v.7 no.3
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• pp.248-253
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• 2023

An efficient global optimization approach for a periodic plasmonic nanoslit array based on extraordinary optical transmission within an acceptable time range is proposed using 𝚀 factor analysis method. The particle swarm optimization is employed as a global optimization tool. The figure of merit is defined as a product of transmission peak value and 𝚀 factor. The design variables are the slit width, height, and period of the slit array, respectively. The optical properties such as transmission spectrum and bandwidth are calculated rigorously using the finite element method.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.186-186
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• 2012

This report investigates a new synthetic route and the size-dependent optical and electrical properties of PbS nanocrystal quantum dots (NQDs) in diameters ranging between 1.5 and 6 nm. Particularly we synthesize ultra-small sized PbS NQDs having extreme quantum confinement with 1.5~2.9 nm in diameter (2.58~1.5 eV in first exciton energy) for the first time by adjusting growth temperature and growth time. In this region, the Stokes shift increases as decreasing size, which is testimony to the highly quantum confinement effect of ultra-small sized PbS NQDs. To find out the electrical properties, we fabricate self-assembled films of PbS NQDs using layer by layer (LBL) spin-coating method and replacing the original ligands with oleic acid to short ligands with 1, 2-ethandithiol (EDT) in the course. The use of capping ligands (EDT) allows us to achieve effective electrical transport in the arrays of solution processed PbS NQDs. These high-quality films apply to Schottky solar cell made in an glass/ITO/PbS/LiF/Al structure and thin-film transistor varying the PbS NQDs diameter 1.5~6 nm. We achieve the highest open-circuit voltage (＜0.6 V) in Schottky solar cell ever using PbS NQDs with first exciton energy 2.58 eV.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1343_1344
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• 2009

In this work, transparent conducting Al-doped zinc oxide (AZO) films were prepared on Corning glass substrate by RF magnetron sputtering using an Al-doped ZnO target (Al: 2 wt.%) at room temperature and all films were deposited with athickness of 150 nm. We investigated the effects of the post-annealing temperature and the annealing ambient on structural, electrical and optical properties of AZO films. The films were annealed at temperatures ranging from 300 to $500^{\circ}C$ in steps of $100^{\circ}C$ using rapid thermal annealing equipment in oxygen. The thickness of the film was observed by field emission scanning electron microscopy (FE-SEM) and grain size was calculated from the XRD spectra using the Scherrer equation and their electrical properties were investigated using a hole measurement and the reflectance of AZO films was investigated by UV-VIS spectrometry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.143-146
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• 2003

Al doped Zinc Oxide(ZnO:Al) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, liquid crystal display, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. The influence of the substrate temperature, working gas pressure and discharge power on the electrical, optical and morphological properties were investigated experimentally. The consideration on the effect of doping amounts of Al on the electrical and optical properties of ZnO thin film were also carried out. ZnO:Al films with the optimum growth conditions showed resistivity of $9.42{\times}10^{-4}\;{\Omeg}-cm$ and transmittance of 90.88% for 840nm in film thickness in the wavelength range of the visible spectrum.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1556-1559
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• 2005

Indium-tin oxide (ITO) films were deposited by a low-frequency (LF, 100 Hz) magnetron sputtering on glass substrates at the room temperature. The effects of the film thickness on the structural, electrical and optical properties of ITO films were investigated. With the film thickness the films reveal better crystallinity, showing both (222) and (400) pla nes in the XRD pattern. The optical transmittance and the sheet resistance of the films decreased with the increasing thickness. In addition, the electrical properties of ITO films were improved after annealing in a vacuum.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.77-83
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• 2013

In this study, we aimed to determine the optical properties of the plasma used for the dry cleaning method. The optical properties of the atmospheric pressure plasma device were measured through the degree of ionization of hydrogen or nitrogen gas by ionized atmospheric gas. The degree of ionization of hydrogen or nitrogen is closely associated with surface modification. We observed through our experiments that argon gas, an atmospheric gas, caused an increase in the ionization of nitrogen gas, which has similar ionization energy. This type of increase in nitrogen gas ions is believed to affect surface modification. The results of our study show that the pressure of argon gas and the partial pressure of argon and nitrogen gases lead to different results. This important result shows that argon ions can affect the ionization of nitrogen gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.1-5
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• 2000

Optical and electrical properties of GaSe:Er\ulcorner single crystals grown by the Bridgenman technique have been investigated by using optical absorption and h\Hall-effect measurement system. The Hall coefficients were mea-sured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration show the characteristic of a partially compensated p-type semiconductor. Carrier density(N\ulcorner) of GaSe doped with Erbium was measured about 3.25$\times$10\ulcorner [cm\ulcorner] at temperature 300K, which was higher than undoped specimen. Photon energy gap (E\ulcorner) of GaSe:Er\ulcorner specimen was measured about 1.79eV.

• Journal of the Korean Ceramic Society
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• v.52 no.3
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• pp.224-227
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• 2015

In this work, the properties of Indium-Zinc-Tin-Oxide (IZTO) thin films, deposited on polyethylene naphthalate (PEN) with a $SiO_2$ buffer layer, were analyzed with different working pressures. After depositing the $SiO_2$ buffer layer on PEN substrates by plasma-enhanced chemical vapor deposition (PECVD), the IZTO thin films were deposited by RF magnetron sputtering with 1 to 7-mTorr working pressure. All the IZTO thin films show an amorphous structure, regardless of the working pressure. The best morphological, electrical, and optical properties are obtained at 3-mTorr working pressure, with a surface roughness of 2.112-nm, a sheet resistance of $8.87-{\Omega}/sq$, and a transmittance at 550-nm of 88.44%. These results indicate that IZTO thin films deposited on PEN have outstanding electrical and optical properties, and the PEN plastic substrate is a suitable material for display devices.