• 한국전기전자재료학회논문지
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• 제22권4호
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• pp.323-326
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• 2009

We have developed blue-emitting phosphorescent organic light emitting diodes (OLEDs) using 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and tris (8-quinolinolato)aluminum ($Alq_3$) electron transport layers. As blue dopant and host materials, bis[(4,6-di-fluorophenyl)-pyridinate-N,C2']picolinate (FIrpic) and N,N'-dicarbazolyl-3,5-benzene (mCP) were used, respectively. The driving voltage, current efficiency and emission characteristics of devices were investigated. While the driving voltage was about $1{\sim}2$ V lower in the device with an $Alq_3$ layer, the current efficiency was about 66 % higher in the device with BCP electron transport layer. the blue phosphorescent OLED with BCP layer exhibited higher purity of color, resulting from a relatively weak electroluminescence intensity at 500 nm.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.599-601
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• 2004

A new blue electroluminescent conjugated polymer, poly(BP-alt-BCV), was prepared by Hornor-Emmons polycondensation and used as a host polymer for the phosphorescent dopant, $(bsn)_2Ir(acac)$. Poly(N-vinylcarbazole) (PVK), known as a blue EL material, was also used for comparison with poly(BP-alt-BCV). Electrophosphorescence of PLEDs with these dopant/host systems was investigated in terms of luminescence, efficiency, emission color, and energy transfer.

• Journal of Information Display
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• 제12권3호
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• pp.141-144
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• 2011

To improve the performance of blue fluorescent and green phosphorescent organic light-emitting diode devices, Merck developed novel green phosphorescent host and electron-transporting materials. The newly developed electron-transporting material improves the external quantum efficiency of blue fluorescent devices up to 8.7%, with an excellent lifetime. In combination with the newly developed host materials, the efficiency of green phosphorescent devices can be improved by a factor of 1.7, and the lifetime by a factor of 7.

• 천문학회보
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• 제41권2호
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• pp.59.1-59.1
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• 2016

Blue Straggler Stars(BSS) affect their host star cluster in various parameters like color, dynamics, etc. For this reason, it is important to know how to relate BSS frequency and evolution of their host stellar system. To statistical study about global properties of open clusters as the environments of BSS formation, we use three catalogues - (1) two galactic open clusters catalogues including BSS candidate, (2) Milky Way Star Cluster (MWSC) survey data. Then, we compare with the data of two BSS catalogues for test of the result of Marchi et al. 2006. We also investigate the radial mass distribution in open cluster, because it is possible that changing the gradient of radial mass distribution cause increasing the BSS frequency. When we group the open cluster into having BSS or not and other criteria, the groups show slight discrepancies, but we show some important results.

• 한국식물병리학회지
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• 제10권2호
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• pp.148-150
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• 1994

Anthracnose of statice (Limonium sp. var. Misty Blue and L. sinuatum Mill. cv. Early Blue) occurred up to 20% in vinyl-houses at Buan, Imsil and Namwon from July to November, 1993. All isolates from the anthracnose symptoms were identified as Glomerella cingulata (Stonem.) Spauld. & Schrenk and its anamorph was Colletotrichum gloeosporioides (Pens.) Sacc. Pathogenicity of the isolates was ascertained on the statice host by artificial inoculation. The symptoms on leaves appeared as circular brown spots in early stage and developed to zonate spots. The spot aggregated and diseased leaves were blighted. The symptom also developed on the stems of severely infected plants and the infected branches were blighted. A lots of acervuli developed on the lesions of stems. Acervuli on necrotic lesions were setose, rounded and elongated. Setae variable in length, 1~4 septate, brown, slightly swollen at the base and tapered to the apex on which conidia were occasionally borned. Statice was revealed as the new host of G. cingulata.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.192-195
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• 2009

We developed highly efficient blue PHOLEDs with reduced roll-off by using a mixed host structure. The balanced charge carrier injection and the distributed recombination zone within emissive layer resulted in a highly stable efficiency roll-off with quantum efficiencies of 20.1 and 18.1 % at a luminance of 1000 and 10000 cd/$m^2$.

• 한국전기전자재료학회논문지
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• 제27권6호
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• pp.377-382
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• 2014

We have investigated the effects of spacer layer inserted between blue and red doped emission layers on the emission and efficiency characteristics of phosphorescent OLEDs. N,N'-di-carbazolyl-3,5-benzene (mCP) was used as a host layer. Iridium(III)bis[(4,6-di-fluorophenyl)- pyridinato-N,$C^2$']picolinate (FIrpic) and tris(1-phenyl-isoquinolinato-$C^2$,N)iridium(III) [Ir(piq)3] were used as blue and red dopants, respectively. The emission layer structure was mCP (1-x) nm/mCP:$Ir(piq)_3$ (5 nm, 10%)/mCP (x nm)/mCP:FIrpic (5 nm, 10%). The thickness of mCP spacer layer was varied from 0 to 15 nm. The emission from $Ir(piq)_3$ and the efficiency of the device were dominated by energy transfer from mCP host and FIrpic molecules, and by diffusion of mCP host triplet excitons.

• 한국수산과학회지
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• 제18권6호
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• pp.581-585
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• 1985

1981년 8월에서 1982년 5월까지 일본 암수현 대퇴만에서 섶 속살이게, Pinnotheres pholadis에 기생된 진주담치를 정기적으로 채집하고 기생군과 비기생군간의 각장에 대한 육중의 상관관계를 조사하고, 그 성숙도와 영양상태의 차를 조직학적 방법에 의해 구명했다. 섶 속살이게의 기생으로 말미암아 진주담치는 증육에 명백한 장해를 받음이 밝혀졌다. 또한, 생식선의 발달이 늦어질뿐 아니라, 생식세포의 수가 감소됨으로써 전체면적에 대한 생식선의 면적비가 낮아지게 되므로, 기생군의 번식력은 비기생군에 비해 현저하게 약한 것으로 추정된다.

• 대한화학회지
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• 제54권3호
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• pp.291-294
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• 2010

본 연구에서는 다양한 농도의 BCzVBi를 청색 형광도판트, DPVBi를 청색 호스트 물질로 적용한 청색OLED 소자를 제작하였다. 최적화된 고효율 청색 OLED 소자의 적층 구조는 NPB (500 ${\AA}$)/DPVBi:BCzVBi-6%(150 ${\AA}$)/$Alq_3$(300 ${\AA}$)/Liq(20 ${\AA}$)/Al (1000 ${\AA}$)으로 구성되었다. 청색 OLED의 최대휘도는 구동전압 13.8V에서13200 cd/$m^2$이고 전류밀도 및 최대효율은 각각 1000 cd/$m^2$의 휘도에서 26.4 mA/$cm^2$, 구동전압 3.9 V에서 4.24 cd/A 이었다. 도핑된 청색 OLED 소자의 발광효율은 도핑되지 않은 소자의 2배에 이른 반면 색좌표는 (0.16, 0.19)로 서로 비슷하였다. BCzVBi가 6% 도핑된 청색 OLED 445 nm와 470 nm에 2개의 EL 스펙트럼의 Peak이 존재하는 반면 도핑되지 않은 순수한 DPVBi 청색OLED 소자는 456 nm에서의 유일한 Peak만을 보여주고 있다. 이는 호스트 물질인 DPVBi의 LUMO와 도판트 물질인 BCzVBI의 LUMO 사이에 분자 진동에 의한 페르스터 에너지 전이에 기인한 것이다.

• 한국전기전자재료학회논문지
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• 제26권6호
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• pp.451-456
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• 2013

To study emission properties of white phosphorescent organic light emitting devices (PHOLEDs), we fabricated white PHOLEDs of ITO(150 nm) / NPB(30 nm) / TcTa(10 nm) / mCP(7.5 nm) / light-emitting layer(25 nm) / UGH3(5 nm) / Bphen(50 nm) / LiF(0.5 nm) / Al(200 nm) structure. The total thickness of light-emitting layer with co-doping and blue-doping/co-doping using a host-dopant system was 25 nm and the dopant of blue and red was FIrpic and $Bt_2Ir$(acac) in UGH3 as host, respectively. The OLED characteristics were changed with position and thickness of blue doping layer and co-doping layer as light-emitting layer and the best performance seemed in structure of blue-doping(5 nm)/co-doping(20 nm) layer. The white PHOLEDs showed the maximum current density of $34.5mA/cm^2$, maximum brightness of $5,731cd/m^2$, maximum current efficiency of 34.8 cd/A, maximum power efficiency of 21.6 lm/W, maximum quantum efficiency of 15.6%, and a Commission International de L'Eclairage (CIE) coordinate of (0.367, 0.436) at $1,000cd/m^2$.