• Title/Summary/Keyword: luminescent

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Recent Progress in Luminescent Lanthanide Complexes for Advanced Photonics Applications

  • Kim, Hwan-Kyu;Oh, Jae-Buem;Baek, Nam-Seob;Roh, Soo-Gyun;Nah, Min-Kook;Kim, Yong-Hee
    • Bulletin of the Korean Chemical Society
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    • v.26 no.2
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    • pp.201-214
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    • 2005
  • We have designed and developed novel luminescent lanthanide complexes for advanced photonics applications. Lanthanide(III) ions (Ln$^{3+}$) were encapsulated by the luminescent ligands such as metalloporphyrins and naphthalenes. The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to Ln$^{3+}$ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of Ln$^{3+}$ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent Ln$^{3+}$ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent Ln$^{3+}$ complexes, yielding novel Ln(III)-cored dendrimer complex. The novel Ln(III)-cored dendrimer complex has much higher PL intensity than the corresponding simple complex, due to the efficient site-isolation effect. In this article, we will deal with recent progress in the synthesis and photophysical studies of inert and stable luminescent Ln$^{3+}$ complexes for advanced photonics applications. Also, our review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to Ln$^{3+}$ ions with Ln(III)-chelated prototype complexes.

White Light Emitting Diodes for Illumination

  • Choi, Kyoung-Jae;Park, Joung-Kyn;Kim, Kyung-Nam;Kim, Chang-Hae;Kim, Ho-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1090-1092
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    • 2006
  • There is provided white light illumination system including a radiation source, a first luminescent material having a peak emission wavelength of about 575 to about 620 nm, a second luminescent material having a peak emission wavelength of about 495 to about 550 nm, which is different from the first luminescent material and a third luminescent material having a peak emission wavelength of about 420 to about 480 nm, which is different from the first and second luminescent materials. The LED may be a UV LED and the luminescent materials may be a blend of three phosphors. A human observer perceives the combination of the blue, green and red phosphor emissions as white light.

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Luminescent Lanthanide Complexes for Advanced Photonics Applications

  • Eom, Yu Kyung;Ryu, Jung Ho;Kim, Hwan Kyu
    • Rapid Communication in Photoscience
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    • v.1 no.1
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    • pp.1-9
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    • 2012
  • Luminescent lanthanide complexes have been overviewed for advanced photonics applications. Lanthanide(III) ions ($Ln^{3+}$) were encapsulated by the luminescent ligands such as metalloporphyrins, naphthalenes, anthracene, push-pull diketone derivatives and boron dipyrromethene(bodipy). The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to $Ln^{3+}$ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of $Ln^{3+}$ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent $Ln^{3+}$ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent $Ln^{3+}$ complexes, yielding novel $Ln^{3+}$-cored dendrimer complex such as metalloporphyrins, naphthalenes, and anthracenes bearing the Fr$\acute{e}$chet aryl-ether dendrons, namely, ($Er^{3+}-[Gn-Pt-Por]_3$ (terpy), $Er^{3+}-[Gn-Naph]_3$(terpy) and $Er^{3+}-[Gn-An]_3$(terpy)). These complexs showed much stronger near-IR emission bands at 1530 nm, originated from the 4f-4f electronic transition of the first excited state ($^4I_{13/2}$) to the ground state ($^4I_{15/2}$) of the partially filled 4f shell. A significant decrease in the fluorescence of metalloporphyrins, naphthalenes and anthracene ligand were accompanied by a strong increase in the near IR emission of the $Ln^{3+}$ ions. The near IR emission intensities of $Ln^{3+}$ ions in the lanthanide(III)-encapsulated dendrimer complexes were dramatically enhanced with increasing the generation number (n) of dendrons, due to the site-isolation and the light-harvesting(LH) effects. Furthermore, it was first attempted to distinguish between the site-isolation and the light-harvesting effects in the present complexes. In this review, synthesis and photophysical studies of inert and stable luminescent $Ln^{3+}$ complexes will be dealt for the advanced photonics applications. Also, the review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to $Ln^{3+}$ ions with $Ln^{3+}$-chelated prototype complexes.

Enhanced Light Outcoupling on Photo-luminescent Devices with Microcavity (Microcavity 적용 광자 발광 소자의 광 추출 향상 연구)

  • Lee, Han Byul;Lee, Eun Hye;Sung, Min Ho;Ryu, Si Hong;Lee, Seong Eui
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.5
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    • pp.391-396
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    • 2013
  • Recently, microcavity is studied to reduce the optical loss of BLU and OLED. In this paper, we suggest applying microcavity to photo-luminescent lamp with plasma discharge technology to meet the display applications for a BLU for LCD. The structure of photo-luminescent lamp consists of SUS foil and ITO glass with microcavity. The opto-electric characteristics of photo-luminescent lamp with microcavity was evaluated. The brightness of photo-luminescent device was increased over $111cd/m^2$ with the adaptation of patterned microcavity at $30{\mu}m$. The 3D optical simulation verified the enhanced light outcoupling when microcavity applied to the device.

Study of Efficiency Test and Subjective Responses about Pendent Task Lighting System Using Phosphor Luminescent Film LED (광기여 필름 LED 팬던트 작업조명시스템 주관평가와 성능검증)

  • Cha, Kwang-Seok;Kim, Hway-Suh
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.3
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    • pp.188-193
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    • 2011
  • For a long time work or study, pendent task lighting system prepared with phosphor luminescent film LED was developed for eye protection and working efficiency improvement. Developed lighting system was used together with pendent and ambient lighting. Such as, we made comfortable lighting environment system. Evaluation for developed lighting system, that had proceeded to Mock-up test and subjective evaluation. Also It had proceeded that lighting environment analyzed and compatibility valuation of installation. In subjective evaluation, the students have expressed themselves satisfied to phosphor luminescent film LED lighting system. In Mock-up test, It is not problem to intensity of illumination, luminance and color temperature. Therefore, developed LED lighting system was installed at the Daegu apartment. It is having a P.O.E study progress to phosphor luminescent film LED lighting system.

Study of Implementation of Broadband Antireflection Coating for Luminescent Solar Concentrators to Optimized the Efficiency

  • Duy, Song Ngo
    • International journal of advanced smart convergence
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    • v.11 no.2
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    • pp.59-63
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    • 2022
  • In this study, we study of luminescent solar concentrators comprise thick glass with broadband antireflection coating deposited on the top surfaces and inorganic phosphor layers contacted on the bottom surfaces. Solar cells are contacted to the lateral surfaces of the glass. Experimental results show the broadband antireflection coating increased the short-circuit current of the solar cell.

Effects of heat treatment and substrates on luminescent characteristics of $ZnGa_O_4:Mn$ thin film phosphor (열처리조건과 기판이 $ZnGa_O_4:Mn$ 박막 형광체의 발광특성에 미치는 영향)

  • Chung, Sung-Mook;Kim, Young-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05a
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    • pp.181-184
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    • 2004
  • The green emitting phosphor, $ZnGa_2O_4:Mn$ thin film with spinel structure were deposited by rf magnetron sputtering. Thin film phosphors were heat-treated in nitrogen, vacuum and air atmosphere, respectively. The effects of the substrates, heat-treatment conditions and the sputtering parameters were investigated. The growing behavior and luminescent properties of thin films depend on the crystallinity of the substrates. The Ga/Zn atomic ratios and luminescent characteristics were dependent on the annealing conditions.

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Measurement of Human Cytochrome P450 Enzyme Induction Based on Mesalazine and Mosapride Citrate Treatments Using a Luminescent Assay

  • Kim, Young-Hoon;Bae, Young-Ji;Kim, Hyung Soo;Cha, Hey-Jin;Yun, Jae-Suk;Shin, Ji-Soon;Seong, Won-Keun;Lee, Yong-Moon;Han, Kyoung-Moon
    • Biomolecules & Therapeutics
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    • v.23 no.5
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    • pp.486-492
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    • 2015
  • Drug metabolism mostly occurs in the liver. Cytochrome P450 (CYP) is a drug-metabolizing enzyme that is responsible for many important drug metabolism reactions. Recently, the US FDA and EU EMA have suggested that CYP enzyme induction can be measured by both enzymatic activity and mRNA expression. However, these experiments are time-consuming and their interassay variability can lead to misinterpretations of the results. To resolve these problems and establish a more powerful method to measure CYP induction, we determined CYP induction by using luminescent assay. Luminescent CYP assays link CYP enzyme activity to firefly luciferase luminescence technology. In this study, we measured the induction of CYP isozymes (1A2, 2B6, 2C9, and 3A4) in cryopreserved human hepatocytes (HMC424, 478, and 493) using a luminometer. We then examined the potential induction abilities (unknown so far) of mesalazine, a drug for colitis, and mosapride citrate, which is used as an antispasmodic drug. The results showed that mesalazine promotes CYP2B6 and 3A4 activities, while mosapride citrate promotes CYP1A2, 2B6, and 3A4 activities. Luminescent CYP assays offer rapid and safe advantages over LC-MS/MS and qRT-PCR methods. Furthermore, luminescent CYP assays decrease the interference between the optical properties of the test compound and the CYP substrates. Therefore, luminescent CYP assays are less labor intensive, rapid, and can be used as robust tools for high-throughput CYP screening during early drug discovery.

Development of Marine Toxicity Standard Method for Marine Luminescent Bacteria: Introduction of N-Tox test (해양성 발광박테리아를 이용한 해양환경 독성평가 시험법 개발: N-Tox test)

  • Lee, Kyu-Tae;Park, Gyung-Soo;Kim, Pyoung-Joong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.2
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    • pp.156-163
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    • 2008
  • Luminescent bacterial toxicity test was first introduced in the early 1980s, registered as international standard method in 1998 and now widely used as a common toxicity test method. This toxicity test uses luminescent bacterium, Vibrio fischeri, originated from marine environment as a test organism. The degree of toxicity can be evaluated from the comparison of luminescent emission intensity between control and treatment groups to toxicants and materials from various environmental matrix for 30 min. This test can be carried out by using commercial products and its results are sensitive and precise. This research is on the feasibility of adopting luminescent bacterial test as a domestic standard test protocol. Using commercial products, a series of experiments were conducted to identify the precision and accuracy of injection volume and light emission, and to evaluate concentration-response relationship between chemical concentrations and light emissions. Also, the feasibility of the application to environmental media and quality assurance/quality control were checked. The results of serial toxicity tests revealed that the preliminary luminescent bacterial toxicity test was robust and suitable as a standard method.