• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.133-136
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• 2003

New porphyrin square (1) was prepared by reaction of porphyrin containing pyridine and $Re(CO)_5Cl$ in THF/toluene solvent. 2-(Methylenel5-crown-5)-nicotinoly ester(2) was synthesized by reaction of 2-(Hydroxymethyl-15-crown-5 and nicotinoly chloride in $CH_2Cl_2$. In fluorescence quenching studies luminescence was quenched by addition of the guest(2) into host(l). In the host-guest system we could obtain binding constant (K=$1.13{\times}10^7M^{-1}$) at decreasing concentration of (2). But the luminescence was dramatically increased after $Na^+$ was added into the host-guest system.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1433-1436
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• 2009

Film morphology, crystallinity, and luminescence property of solution processed ZnO films have been studied. Fluorine addition and annealing ambient significantly change the defect-related emission band as well as the structural property. Using the overall emission behaviors, we can predict an optimized process condition for solution-based ZnO thin film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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• pp.82-85
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• 2005

Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study, we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.145-150
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• 2005

This study was carried out to examine the properties of sample amount and storage conditions on the accumulated pulsed photostimulated luminescence (PPSL) signals of soybean paste powder. Difference amounts (0.1, 0.5 and 1 g) of soybean paste powder samples stored in normal room and darkroom conditions were measured. The PPSL signals of the soybean paste powders significantly increased with irradiation dose up to 10 kGy. The PPSL signals of irradiated soybean paste powder samples decreased with increasing storage periods. The decay rates were similar to regardless of storage conditions and sample amount. The PPSL signals of the irradiated soybean paste powder measured for 120 s were higher than those measured for 60 s. These results indicated that although the PPSL signal of all soybean paste powder samples decreased with increasing storage time, detection of irradiated samples was still possible after 12 months of storage regardless of sample amount and measurement times in both normal room and darkroom conditions.

• 한국전기전자재료학회논문지
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• 제14권11호
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• pp.928-933
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• 2001

Perdeuterated hexaflouroacetylacetonato-ytterbium [Yb(SOL-D)$_3$] complexes are synthesized by the keto-enol tautomerism reaction of Yb(SOL-H)$_3$ in methanol-d$_4$ in order to reduce the radiationless transition to the ligands for the high power solid state laser material. The luminescence properties of Yb(SOL-D)$_3$ complex are measured in the following anhydrous deuterated organic solvents ; Methanol-d$_4$, THF-d$_{8}$, PO(O$CH_3$)$_3$ and DMSO-d$_{6}$. The Luminescence intensity, lifetime and quantum efficiency in DMSO-d$_{6}$ are superior to those in other deuterated solvents. It is suggested that the anhydrous DMSO-d$_{6}$ might be the most appropriate solvent for the laser material of Yb(SOL-D)$_3$ complex.complex.

• The Korean Journal of Ceramics
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• 제2권3호
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• pp.137-141
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• 1996

Ambient air aged anodically etched porous silicon (PS) and spark-processed silicon (sp-Si) show interesting similarities and dissimilarities in some of their luminescence-related properties. Among these similarties are: (1) the photoluminescence (PL) peak maximum in the blue/violet (410 nm);(2) the blue/violet PL peak positions are essentially unchanged with temperature ; (3) PL decay times in the nanosecond region which are independent of the detection wavelength, which is much faster in decay times compared to that of observed decay time in $SiO_2$.Among the dissimilarities are: (1) the PL intensity of blue/violet luminescence, namely, the PL intensity of sp-Si is at least 2 orders of magnitude larger than that of an ambient air aged PS; (2) the blue/violet PL intensity of sp-Si is more stable than that of ambient air aged PS under UV illuminations; (3) FTIR spectra of sp-Si favor those modes, which involve silicon -oxygen bonds in $SiO_2$ stoichiometry, whereas ambient air aged PS can be considered as a nonstoichiometric oxide judging from the observed vibrational spectra.

• 한국식품저장유통학회지
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• 제8권3호
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• pp.291-295
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• 2001

방사선 처리의 가능성이 높은 농산물로서 곡류(현미, 메밀)와 두류(대두, 땅콩, 적두, 녹두)는 국산과 중국산을, 마늘은 국산을 대상으로 하여 곡류와 두류는 0.5∼4 kGy, 마늘은 0.05∼0.5 kGy 범위의 감마선을 각각 조사하고 조사여부의 검지를 위한 광자극 발광 특성(PSL)을 검토하였다. 곡류와 녹두의 PSL 값은 대체로 비조사군(< 700 photon counts, negative)과 조사군(> 5,000 counts, positive)의 중간 값을 보여 PSL 검지법의 적용이 불가능한 것으로 나타났다. 그러나 대두, 땅콩, 적두 및 마늘은 비조사군은 700 court군 이하, 감마선 조사구는 5,000 이상의 photon count를 나타내어 조사 여부의 건지에 광자극 발광분석의 적용이 가능하였다 본 실험에 사용된 곡류와 두류의 감마선 조사에 따른 광자극 발광 특성은 원산지 별로 차이가 없었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.155-159
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• 2003

The preparation and luminescence characterization of yttrium oxide doped with trivalent europium phosphors by sol-gel method have been investigated. Aqueous metal nitrate solution was mixed with EDTA which was chosen by the most suitable material of sol-gel formation one of appled various chelating agents. we noticed that the samples when are heated with EDTA at a temperature of $100^{\circ}C$ for 1hrs, produced brownish and crisp powders due to condensation reaction on decomposition, dehydration and formation of sol-gel. Hence, when the powder pre-heated was then heated at $1200^{\circ}C$ for 3hrs in atmosphere, the luminescence characterization of resultant $Y_{2}O_{3}:Eu^{3+}$ phosphor was enhanced upto maximum 30% significantly than conventional method through increasing porous region and decreasing particle sizes.

• 한국전기전자재료학회논문지
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• 제17권9호
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• pp.988-993
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• 2004

Luminescence characteristics of Ag-doped ZnO as the quantum dot materials to increasing the efficiency on dye-sensitized solar cells (DSC) have been studied. Ag doped ZnO powder was produced by the self-sustaining combustion process using ultrasonic spraying heating method. Luminescence wavelength region of the ZnO by Ag doping was shifted to longer wavelength. Tn the case of the Ag doped ZnO powder, broad luminescence spectrum centered on 600nm was observed. On the other hand, we compared PL data of RTA treated ZnO:Ag film at various temperatures because the front electrode of solar cell was in need of the sintering process. In XRD and PL data for RTA treated film at the 500$^{\circ}C$ showed good property. And, it was found that the grain size wasn't growing but only optical property was changed. According to the result of XRD, PL, absorption, emission spectrum and DV-X${\alpha}$ used in theoretical calculation, it is considered to be possible to use Ag doped ZnO as quantum dot material for improving DSC efficiency.

• 한국재료학회지
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• 제30권8호
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• pp.413-420
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• 2020

Lu₃Al_5-xGa_xO₁₂:Ce³⁺,Cr³⁺ powders are prepared using a solid-state reaction method. To determine the crystal structure, Rietveld refinement is performed. The results indicate that Ga³⁺ ions preferentially occupied tetrahedral rather than octahedral sites. The lattice constant linearly increases, obeying Vegard's law, despite the strong preference of Ga³⁺ for the tetrahedral sites. Increasing x led to a blue-shift of the Ce³⁺ emission band in the green region and a change in the emission intensity. Persistent luminescence is observed from the powders prepared with x = 2-3, occurring through a trapping and detrapping process between Ce³⁺ and Cr³⁺ ions. The longest persistent luminescence is achieved for x = 2; its lifetime is at least 30 min. The findings are explained using crystal structure refinement, crystal field splitting, optical band gap, and electron trapping mechanism.