http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이용석,김훈,서태훈,박아현,Seul Be Lee,정상조,최철종,서은경 대한금속·재료학회 2013 ELECTRONIC MATERIALS LETTERS Vol.9 No.5
We have studied the structural anisotropic characteristics of epitaxially laterally overgrown (ELOG) a-plane GaN epilayer on r-plane sapphire substrate with two different SiO2-stripe orientations using metal organic chemical vapor deposition. The SiO2 stipe patterns were made along [0001] and [1100] crystographilic orientations of GaN which correspond to [1101] and [1120] directions of r-plane sapphire, respectively. The ELOG a-plane GaN on [0001]-stripe orientation reveals symmetric morphology in the extent of lateral overgrowth compared to that grown on [1100]-oriented stripe. Threading dislocation and basal stacking fault densities in wing region were ~8 × 107 cm−2 and ~5.2 × 104 cm−1, respectively. Raman measurement of the fully coalesced a-plane GaN indicated a compressive strain of about 0.39 Gpa in the window region.
권유빈,이상룡,서태훈,김영관 한국고분자학회 2022 Macromolecular Research Vol.30 No.4
A strong graphene oxide (GO)-based artificial nacre is developed by using a simple and efficient interfacial chemistry. GO is simultaneously reduced and functionalized with tannic acid (TA) and the resulting TA-reduced GO (TA-RGO) exhibits a high aqueous dispersibility owing to abundant phenol groups. TA-RGO sheets are incorporated with poly(vinyl alcohol) (PVA) and then assembled into an artificial nacre-like structure by vacuum-assisted filtration to induce the formation of multidentate interfacial hydrogen bonding between TA-RGO and PVA. Based on the multidentate hydrogen bonding, the resulting TA-RGO/ PVA (1 wt%) composite film presented an overall and efficient reinforcement of tensile strength (186.1 ± 12.8 MPa), modulus (15.2 ± 1.2 GPa) and toughness (1546 ± 248 kJ/m3) compared to those of GO (83.3 ± 5.4 MPa, 8.9 ± 0.4 GPa and 1434 ± 152 kJ/m3) and TA-RGO (87.6 ± 10.6 MPa, 13.8 ± 1.4 GPa and 306 ± 51 kJ/m3), respectively. The present study demonstrates the rational design of interfacial interaction can greatly improve the performance of a structural composite material.
Yong Seok Lee,서태훈,박아현,이강재,Sang Jo Chung,Eun-Kyung Suh 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.3
The influence of the epitaxial growth rate on the surface morphology, as well as the crystallinity and optical properties of nonpolar a-plane GaN epilayers grown on r-plane sapphire substrate, has been investigated by x-ray diffraction and photoluminescence studies. The a-plane GaN epilayer grown at faster growth rates revealed a horizontal-pillar-shaped morphology with triangular-pits having sharp corners. While the epilayer grown at a faster growth rate showed a greater difference in the ω tilt-offset angle and line-width value between the on- and off-axes from x-ray diffraction, the a-plane GaN grown at the relatively slower growth rate showed a flat morphology with few pits and small ω tilt-offset difference. Growth of nonpolar a-plane GaN epilayer was optimized, and the effect of the growth rate of the a-plane GaN epilayer and the reason for the difference in the ω tilt-offset line-width value between the c- and m-direction mosaicity of x-ray diffraction were analyzed.
전준모,최민식,김슬비,서태훈,구본철,류성우,박지훈,김영관 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.102 No.-
This paper demonstrates eggshell membrane protein hydrolysate (ESMH), a critical food wasteworldwide, can be harnessed as a multifunctional agent for eco-friendly reduction and functionalizationof graphene oxide (GO) based on its diverse and abundant functional groups. The resulting GO reducedand functionalized with ESMH (ESMH-RGO) exhibits an aqueous dispersibility and applicability as a2-dimensional support for synthesis of catalytic Au nanoparticles (Au NPs) with a high density. TheAuNPs synthesized on ESMH-RGO (AuNPs@ESMH-RGO) presents a high catalytic activity for conversionof environmental pollutant (4-nitrophenol) to an industrially useful raw material (4-aminophenol). Thoseresults clearly indicate that ESMH has a strong potential in environmental and materials chemistry.
Correlation Between Reflectance and Photoluminescent Properties of Al-rich ZnO Nano-Structures
Firoz Khan,백성호,Nafis Ahmad,이건희,서태훈,서은경,김재현 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.3
Al rich zinc oxide nano-structured films were synthesized using spin coating sol-gel technique. The films were annealed in oxygen ambient in the temperature range of 200-700 °C. The structural, optical, and photoluminescence (PL) properties of the films were studied at various annealing temperatures using X-ray diffraction spectroscopy, field emission scanning electron microscopy, photoluminescence emission spectra measurement, and Raman and UV-Vis spectroscopy. The optical band gap was found to decrease with the increase of the annealing temperature following the Gauss Amp function due to the confinement of the exciton. The PL peak intensity in the near band region (INBE) was found to increase with the increase of the annealing temperature up to 600 °C, then to decrease fast to a lower value for the annealing temperature of 700 °C due to crystalline quality. The Raman peak of E2 (low) was red shifted from 118 cm-1 to 126 cm-1 with the increase of the annealing temperature. The intensity of the second order phonon (TA+LO) at 674 cm-1 was found to decrease with the increase of the annealing temperature. The normalized values of the reflectance and the PL intensity in the NBE region were highest for the annealing temperature of 600 °C. A special correlation was found between the reflectance at λ = 1000 nm and the normalized PL intensity in the green region due to scattering due to presence of grains.
오태수,서은경,이용석,정현,김잔디,서태훈 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4
InxAl1-xN ternary lms were grown on GaN/sapphire (0001) templates by using metalorganic chemical vapor deposition (MOCVD) with a In molar fraction in the range of 0.08 ≤ x ≤ 0.22. in Al-rich region. The In molar fraction x was controlled by using the MOCVD growth temperature and pressure. The optical bandgap energies and In molar fractions of InxAl1-xN ternary films were estimated by using high resolution X-ray diffraction and optical reflectance measurements. Our experimental results showed that the InxAl1-xN bandgap energies depended on In molar fraction with a large bowing parameter of 5.3 0.3 eV and that this value was larger than those predicted by using theoretical first-principles calculations. The spatial emission distribution of the InxAl1-xN ternary film was also investigated using cathodo-luminescence measurement at room temperature and showed an emission fluctuation that was possibly due to In segregation.