• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.585-587
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• 2008

Depending on host environments, $Eu^{2+}$ emission can be spectrally tuned by manipulating the energy levels between allowed $4f{\leftrightarrow}5d$ transition. Spectral variations of $Eu^{2+}$ emission from narrow green emission to broad yellow emission band were achieved by varying the host lattices such as Sr- or Ba-silicate, borate, and borosilicate.

• Transactions on Electrical and Electronic Materials
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• 제12권2호
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• pp.84-87
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• 2011

We fabricated phosphorescent organic light-emitting devices with a 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) host layer. Two kinds of devices, one of ITO/TAPC/TAPC:FIrpic/TAZ/LiF/Al (device A) and one of ITO/TAPC:FIrpic/TAPC/TAZ/LiF/Al (device B), were prepared to investigate electrical and optical properties. Iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,$C^{2'}$]picolinate (FIrpic) and 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ) were used as a blue phosphorescent guest material and an electron transport layer, respectively. The TAPC layer in device B strongly contributes to whitish emission, higher driving voltage, and lower current efficiency characteristics compared with device A. The mechanisms of these electrical and optical characteristics of the devices were investigated.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.549-552
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• 2008

We have developed a novel bipolar host material with both electron and hole transporting characteristics. Since CGH(Cheil Green Host) has some electron transporting characteristics, it shows increased luminance efficiency in device including TCTA and without HBL(hole blocking layer:BAlq). Maximum power efficency of CGH was 27.4lm/W at the device structure ITO/DNTPD(60)/NPB(20)/TCTA(10)/EML(30)/Alq3(20)/LIF(1)/Al. We measured device performance again without HBL. The result of CGH showing 26.0lm/W is outstanding compared to that of CBP showing 19.1lm/W without holeblocking layer. We also measured lifetime and found to be 205hr at 3000nit, that is significant result compared to the life time of CBP device showing 82hr. CGH shows high device performance with holeblocking layer. Moreover, it shows better device performance and life time than those of CBP without holeblocking.

• 한국정보통신학회논문지
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• 제16권7호
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• pp.1512-1517
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• 2012

본 논문에서는 Guest-Host 디스플레이의 문제점인 낮은 명암대비비를 해결하기 위해서 음전하로 대전 된 흑색입자를 이용한 고성능 하이브리드 Guest-Host 디스플레이를 제안하였다. 우리는 패턴 된 전극구조의 설계로 전압에 따른 입자의 스위칭을 고려하였으며, 염료 및 입자의 혼합비를 최적화하여 전기광학특성을 향상 시켰다. 따라서 기존 Heilmeier Guest-Host 디스플레이에 비교하여 dark 특성을 80%이상 향상시켰으며, 명암대비비를 비교분석함으로써 제안 된 모드의 성능 우수성을 검증하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1573-1576
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• 2007

ABCV-Py, a new red fluorescent material, in which two identical electron donor (dimethylamino group) and acceptor (cyano group) moieties are linked to two independent biphenyl groups which share the same core phenyl, has been synthesized for use in OLED application. Performance of red doped electroluminescent devices using ABCV-Py as dopant were measured with various host materials, $Alq_3$, CBP, DPVBi, and p-terphenyl. The performance of device with DPVBi host material was better than those with other host materials and high doping concentration could be applied on device with ABCV-Py as dopant.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.863-868
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• 2009

New spiro[fluorene-7,9′-benzofluorene]-based blue host material, 5-phenyl-spiro[fluorene-7,9′-benzofluorene] (BH-1P), was successfully prepared by reacting 5-bromo-spiro[fluorene-7,9′-benzofluorene] (1) with phenyl boronic acid through the Suzuki reaction. 5-(N,N-Diphenyl)amino-spiro[fluorene-7,9′-benzofluorene] (BH-1DPA) and diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)-phenyl]amine (BD-1) were used as dopant materials. 2,5-Bis-(2',2"- bipyridin-6-yl)-1,1-diphenyl-3,4-diphenylsilacyclopentadiene (ET4) and Alq3 were used as electron transfer materials. Their UV absorption, photoluminescence and thermal properties were examined. The blue OLEDs with the configuration of ITO/DNTPD/$\alpha$-NPD/BH-1P:5% dopant/$Alq_3$ or ET4/LiF-Al prepared from the BH-1P host and BH-1DPA and BD-1 dopants showed a blue EL spectrum at 452 nm at 10 V and a luminance of 923.9 cd/$m^2$ with an efficiency of 1.27 lm/W at a current density of 72.57 mA/$cm^2$.

• Applied Microscopy
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• 제17권1호
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• pp.161-168
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• 1987

The elongated filamentous haustorial cells, hyphae, of Cuscuta australis R. Brown penetrated into the vascular tissues of the host plant Trifolium repens L. were studied by the light and electron microscopes. The hyphae reached the host xylem were invaded into the host vessels and then they grew within the host vessels. Finally these hyphae were differentiated into the water conducting elements, xylary hyphae, by thickening of the secondary walls. The hyphae reached the host phloem were branched at the apical regions. These hyphae possessed thin-layered cytoplasm involving the typical features of sieve elements such as the parallel arrays of smooth endoplasmic reticulum, plastids with the clusters of fine starch granules, and mitochondria with the dilated cristae. It was indicated that these hyphae were differentiated into the nutrients conducting elements, phloic hyphae. The structures described were compared with those of other parasitic plants and were discussed in view of the translocation of materials from host to parasite.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.78-78
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• 2016

For the past three decades, extensive research has been performed in the surface design of new polymers for a variety of medical applications. Great progress in therapeutics and diagnostics can be attributed to these scientific advances in biomedical polymers. A variety of bioinert materials or bioactive materials using drugs, cells, and growth factors are widely utilized for the implants, devices and tissue regeneration. These materials provide an improved biocompatible materials to host, to significantly decrease or increase the host/tissue/blood response to the foreign materials. In the future, biomaterials will play a different role in modern therapeutics. New materials will be tailored to interact more on a protein and cellular level to achieve high degree of biocompatibility, biospecificity and bioacitivity. In this presentation, various biocompatible materials based on surface/bulk engineering will be demonstrated, which can be utilized as therapeutics implants and therapeutic vehicles for biologically active molecules such as cell, protein /peptide and gene.

• Journal of Information Display
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• 제5권3호
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• pp.25-29
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• 2004

Effects of additing various types of ceramic fillers to the BZB-based glass on the thermo-chemical stability, optical reflectance, and mechanical properties were investigated. The glass system demonstrated the feasibility to host various types of ceramic fillers to form micro-composites at the processing temperature suitable for PDP systems. The optical reflectance and mechanical strength of the filler-glass composites were improved as compared to the glass itself. These results demonstrate the feasibility of applying the Pb-free BZB-based glass system as a matrix for employing various types of crystalline ceramic fillers to be used as barrier rib materials in plasma display panels.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.628-631
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• 2007

We developed new green emitting materials based on the spiro moieties. The introduction of a spiro linkage into the structure of DJGH series lead to a reduction in crystallization tendency and an increase in glass transition temperature. they showed much better emitting efficiency and color purity than commercial host material $Alq_3$.