• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.77-79
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• 2008

Polynitro fullerenes were synthesized by reaction C-60 in benzen solution with a mixture of NaNO$_2$ and HNO$_3$. Hydrolysis of polynitro fullerenes in aqueous NaOH gave the corresponding polyhydroxylated fullerenes. Sulfonation reaction was carried out in pyridine solution of ClSO$_3$H. Infrared spectra of the resultant fullerene derivatives showed the characteristic IR bands, corresponding to absorptions of O-H, N-O, and SO$_3$Na functions. Electric resistivity and thermal transmittance of wool fiber absorbed with the water-soluble C-60 were investigated. Thermal transmittances of wool fiber were increased with increasing water-soluble C-60 concentrations, but electric conductivity were decreased with raising water-soluble C-60 uptake values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.471-478
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• 2002

Vacuum evaporated cadmium sulphide (CdS) thin films were implanted with $Ar^+$ and $N^+$ for different doses. The properties of the ion implanted CdS thin films have been analysed using XRD, optical transmittance spectra, and Raman scattering studies. Formation of Cd metallic clusters were observed in ion implanted films. The band gap of $Ar^+$ doped films decreased from 2.385 eV of the undoped film to 2.28 eV for the maximum doping. In the case of $N^+$ doped film the band gap decreased from 2.385 to 2.301 eV, whereas the absorption coefficient values increased with the increase of implantation dose. On implantation of both types of ions, the Raman peak position appeared at $299\textrm{cm}^{-1}$ and the FWHM changed with the ion dose.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.154-159
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• 2005

Low RF power density was used for preparing transparent conducting AI-doped ZnO (AZO) thin films by RF Magnetron Sputtering on Corning 1737 glass. The dependence of films' structural, optical and electrical properties on sputtering gas, film's thickness and substrate temperature were investigated. Low percent of incorporated H2 in Ar sputtering gas has proven to reduce film's resistivity and sheet resistance as low as $4.1\times10^{-3}{\Omega}.cm$. It also formed new preferred peaks orientation of (101) and (100) which indicated that the c-axis of AZO films was parallel to the substrate. From UN-VIS-NIR Spectrophotometer analysis, it further showed high optical transmittance at about $\~ 90\%$ at visible light spectra (400-700nm).

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.190-196
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• 1998

Amorphous ternary $Si_xC_yN-z$ thin films were obtained by plasma enhanced chemical vapor deposition(PECVD) using $N_2, SiH_4 \;and \;C_2H_4$ as the reaction sources. The chemical state were characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy(FTIR). The optical properties of the thin films were investigated by UV-visible spectrophotometer and ellipsometer, and the optical band gaps of thin films were determined from corresponding transmittance spectra following Tauc equation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.199-200
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• 2006

Transparent conductive alum mum-doped ZnO (AZO) films have been prepared on polycarbonate (PC), Coring 7059 and Quartz substrates by DC sputtering method at room temperature. Films deposited was evaluated about spectra of X-ray diffraction and transmittance and characteristics of films deposited as kind of substrate was compared. Films deposited showed (002) orientation and all AZO films are transparent over 80% within the visible wavelength region.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.792-797
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• 2009

In this paper, CdS thin films for the use of window layer in solar cell were fabricated by vacuum evaporation method to improve the reproducibility, The electrical and optical properties of thin films with the variations of substrates temperature and the variations of the film thickness were investigated. As increasing the substrates temperature the resistivities of films were increased. The samples transmissivity were shown over 70% when the wavelength were above 500 nm. In the films with 280 nm thickness, its transmissivity were reached 100%. The resistivities of the samples were decreased as increasing its thickness.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2895-2898
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• 2009

The complete structural characterization of dehydrodivanillin, an important natural product of interest to the food, cosmetics and aroma industries, has been carried out using multi-dimensional NMR spectroscopic techniques, and its previously $reported^{13}$C-NMR values have been reassigned. Dense and granular thin films of dehydrodivanillin have been grown by sublimation under high vacuum and studied using Scanning Electron Microscopy (SEM), electrical and optical techniques. The transmittance spectra of the films indicate a wide optical band gap of more than 3 eV. Typical J-V characteristics of Glass/ITO/dehydrodivanillin/Al structure exhibited moderate current densities ${\sim}10^{-4}\;A/cm^2$ at voltages > 25 V with an appreciable SCLC mobility of the order of $10^{-6}\;cm^2$/V-s.

• Applied Science and Convergence Technology
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• v.23 no.1
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• pp.44-47
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• 2014

In this study, we investigated the basic properties of N-doped ethylcyclohexene plasma polymer thin films that deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition (PECVD) method with controlled ammonia flow rate. Ethylcyclohexene was used as organic precursor with hydrogen gas as the precursor bubbler gas. Additionally, ammonia ($NH_3$) gas was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, UV-Visible spectroscopy, and water contact angle measurement. We found that with increasing plasma power, film thickness is gradually increased while optical transmittance is drastically decreased. However, under the same plasma condition, water contact angle is decreased with increasing $NH_3$ flow rate. The FT-IR spectra showed that the N-doped ethylcyclohexene plasma polymer films were completely fragmented and polymerized from ethylcyclohexane.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.261-265
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• 2003

Near-infrared (NIR) system was used to determine rapidly and simply indomethacin in buffer solution for a dissolution test of tablets and capsules. Indomethacin standards were prepared ranging from 10 to 50 ppm using the mixture of phosphate buffer (pH 7.2) and water (1 : 4). The near-infrared (NIR) transmittance spectra of indomethacin standard solutions were collected by using a quartz cell in 1 mm and 2 mm pathlength. Partial least square regression (PLSR) was explored to develop calibration models over the spectral range 1100∼1700 nm. The model using 1 mm quartz cell was better than that using 2 mm quartz cell. The PLSR models developed gave standard error of prediction (SEP) of 0.858 ppm. In order to validate the developed calibration model, routine analysis was performed using another standard solutions. The NIR routine analysis showed good correlation with actual values. Standard error of prediction (SEP) is 1.414 ppm for 7 indomethacin samples in routine analysis and its error was permeable in the regulation of Korean Pharmacopoeia (VII). These results show the potential use of the real time monitoring for indomethacin during a dissolution test.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1644-1654
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• 2018

Eigenvalue distributions for a periodic metal-insulator-metal waveguide, classified into the point spectrum and the discretized continuous spectrum (DCS), are investigated as functions of frequencies, gap widths, and periods. Muller's method is suggested for solving exact eigenvalues, and we propose the scheme for finding proper initial values in the Muller's method by considering only ${\Re}e({\varepsilon}_r)$ in the dispersion equation. We then find that anti-crossing behavior, repulsive effect between the point spectrum and the DCS, becomes stronger when the real parts of the roots in the point spectrum have smaller values. Finally, we examine the transmittances of a single subwavelength slit for real metals using the mode matching technique. The transmittances in real metals similarly follow those of the perfect electric conductor (PEC) at low frequencies, while the patterns at higher frequencies begin to differ from the PEC.