• Journal of Astronomy and Space Sciences
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• v.12 no.1
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• pp.1-13
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• 1995

We carried out photometric and spectroscopic observatious of the blue compact dwarf galaxy Haro 6 in the Virgo Cluster of Galaxies. The long-slit spectroscopy was employed at three position angles, $\Phi$=$0^{\circ}$, $\Phi$=$30^{\circ}$, and $\Phi$=$120^{\circ}$with CCD camera mounted on the Cassegrain Spectrograph. Based on the mean intrinsic axial ratio < $q_0$ >=0.3, we derived inclination I of the system as $44^{\circ}$using our composite V-band CCD image. Careful analysis on the velocity field of the system shows an asymptotically fiat rotation curve with the maximum rotational velocity $V(r)_{max}$ reaches about 12km/sec. The calculation of the dynamical mass of Haro 6 with a simple mass model is briefly discussed with emphasis on the mass to luminosity ratio. From the IRAS Point Source Cataloque, we derived dust-to-gas ratio which indicates relatively low dust content, thus tempting us to conjecture the youth of the system.

• Journal of Information Display
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• v.6 no.1
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• pp.33-36
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• 2005

To obtain various colors from the blue emitting poly(fluorene)s, two different approaches are introduced. One is copolymerization with low band gap comonomers and the other is molecular doping with various dyes. As fast and efficient exciton migration and trapping and/or energy transfer between the chromorphoric segments or doped dyes in conjugated polymers can shift the emission to longer wavelengths, these phenomena can be utilized to obtain various colors from the intrinsically blue light emitting poly(fluorene)s.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.874-876
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• 2003

Blue light-emitting polyfluorene derivatives, poly[9,9-bis(4'-n-octyloxyphenyl) fluorene] (PBOPF), poly[9,9-bis(2'-ethylhexyl)]fluorene (PBEHF) and copolymers of PBOPF and PBEHF were synthesized through Ni(0) mediated polymerization and their light-emitting properties were investigated. The PBEHF thin film showed significant excimer band in PL spectra after thermal annealing at 100 $^{\circ}C$ for 2h. But no significant excimer emission was observed in the PL spectra of the PBOPF and the copolymers even after thermal annealing suggesting that BOPF unit effectively suppressed the excimer emission.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.346.2-346.2
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• 2014

To use the GaN based light-emitting diodes (LEDs) as solid state lighting sources, the improvement of light extraction and internal quantum efficiency is essential factors for high brightness LEDs. In this study, we suggested the new materials system of a zinc tin oxide (ZTO) layer formed on blue LED epi-structures to improve the light extraction. ZTO is a representative n-type oxide material consisted of ZnO and SnO system. Moreover, ZTO is one of the promising oxide semiconductor material. Even though ZTO has higher chemical stability than IGZO owing to its SnO2 content this has high mobility and high reliability. After formation of ZTO layer on p-GaN layer by using the spin coating method, structural and optical properties are investigated. The x-ray diffraction (XRD) measurement results show the successful formation of ZTO. The photoluminescence (PL) and absorption spectrum shows that it has 3.6-4.1eV band gap. Finally, the light extraction properties of ZTO/LED chip using electroluminescence (EL) measurement were investigated. The experimental and theoretical analyses were simultaneously conducted.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.53.1-53.1
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• 2011

We investigate the radial properties of the narrow-line region (NLR) in two radio-quiet quasars, PG1012+008 and PG1307+085, using the spectra obtained with the FORS1 at the Very Large Telescope. These high quality spectra with seeing < 0.6" enable us to extract seven two-pixel (0.4") spectra as a function of the radial distance from the accretion disk. In contrast to [OIII] narrow-band imaging, which can be contaminated by starbursts, shock-ionized gas, and tidal tails, we use emission-line diagnostic to determine the true size of the AGN-excited NLR. In this poster, we present the results based on the radial variance of $H{\beta}$ to [OIII] ${\lambda}5007$ ratio. For both targets, the [OIII] emission line exhibits a blue wing, suggesting an outflow of gas. In the case of PG1307+085, the blue wing disappears at the distance of 1". We will discuss the properties of the NLR in detail.

• Bulletin of the Korean Chemical Society
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• v.16 no.2
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• pp.135-138
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• 1995

A series of new polymers containing phenylenevinylene (PV) units were synthesized by Wittig polycondensation reaction and properties of the synthesized polymers were characterized by FT-IR and UV-visible spectroscopy, and their light-emitting properties were studied. All of the synthesized polymers were soluble in organic solvents and showed good film quality. The absorption maxima and band edges of the polymers were moved to shorter wavelength region by reducing the electron donating alkoxy groups incorporated in phenylenevinylene unit. The photo-induced emission spectra were obtained and all of the polymers revealed their emission in blue region. The observed emission maxima of the polymers were ranged from 480-495 nm.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.214-218
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• 2021

We investigated the optimal stacked structure from the perspective of process architecture (PA) through emission spectrum analysis according to the wavelength of quantum dot (QD)-organic light-emitting diodes (OLED). We confirmed that the blue-light leakage through the QD can be minimized by increasing the QD filling density above a critical value in the red QD (R-QD) layer. In addition, when the thickness of red-color filter (R-CF) at the upper part of the R-QD increased to more than 3 ㎛, the leakage of blue light through the R-CF was effectively blocked, and a very sharp emission spectrum in the red wavelength band could be obtained. According to these outstanding results, we expect that the development of QD-OLED displays with very excellent color gamut can be possibly realized.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.77-78
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• 1996

We perfom a large project for complex study of Blue Compact Galaxies (BCGs) with strong star formation, which includes optical spectroscopy, BVR CCD photometry and HI 21 cm radio survey. The most interesting galaxies are studied also with HST and VLA. In the frame of this project we began the study of H$\alpha$ morphology of BCGs with 6-m telescope. We present and discuss here the results for the first 6 galaxies. We found the noticeable variety of forms for H$\alpha$ morphology comparing to broad band images: from very compact HII region in very center of stellar body (Mark 996, possible dwarf post-merger, old galaxy experiencing strong star formation burst), to very extended gas emission encompassing the whole area traced by stars (SBS 0335-052, the most probable young galaxy in formation).

• Journal of Ceramic Processing Research
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• v.13 no.spc1
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• pp.59-63
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• 2012

Ga2O3-core/CdO-shell nanowires were synthesized by a two step process comprising thermal evaporation of GaN powders and sputter-deposition of CdO. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses revealed that the cores and the shells of the annealed coaxial nanowires were single crystal of monoclinic Ga2O3 and FCC CdO, respectively. As-synthesized Ga2O3 nanowires showed a broad emission band at approximately 460 nm in the blue region. The blue emission intensity of the Ga2O3 nanowires was slightly decreased by CdO coating, but it was significantly increased by subsequent thermal annealing in a reducing atmosphere. The major emission peak was also shifted from ~500 nm by annealing in a reducing atmosphere, which is attributed to the increases in the Cd interstitial and O vacancy concentrations in the cores.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.336-340
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• 2012

Wide band gap p-type hydrogenated amorphous silicon oxide (a-SiO:H) buffer layer has been used at the interface of transparent conductive oxide (TCO) and hydrogenated amorphous silicon (a-Si:H) p-type layer of a p-i-n type a-Si:H solar cell. Introduction of 5 nm thick buffer layer improves in blue response of the cell along with 0.5% enhancement of photovoltaic conversion efficiency (η). The cells with buffer layer show higher open circuit voltage (Voc), fill factor (FF), short circuit current density (Jsc) and improved blue response with respect to the cell without buffer layer.