• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.315-318
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• 1998

Organic light-emitting diodes(OLEDs) or electroluminescent devices have attracted much attention because of their possible application as large-area light-emitting displays. Their structure was based on employing a multilayer device structure containing an emitting layer and a carrier transporting layer of suitable organic materials. In this study, several Tb complexes such as Tb(ACAC)$_3$(Phen), Tb(ACAC)$_3$(Phen-Cl) and Tb(TPB)$_3$(Phen) were synthesized and the photoluminescence(PL) and electroluminescence (EL) characteristics of their thin films were investigated by fabricating the devices having a structure of anode/HTL/terbium-oomplex/ETL/cathode, where TPD was used as an hole transporting and Alq$_3$ and TAZ-Si were used as an electron transporting materials. It was found that the photoluminescence(PL) and electroluminescence(EL) characteristics of these terbium complexes were dependent upon the ligands coordinated to terbium metal. Details on the explanation of electrical transport phenomena of the structure with I-V characteristics of the OLEDs using the trapped-charge-limited current(TCLC) model will be discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1046-1049
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• 2002

In this study, We fabricated Organic Electroluminescence device, in order to improve the efficiency of Blue OLED in the full-color OLED. We made two sample. Sample A is that We used TPD(N,N‘-bis(3-methylphenyl)-N,N'-diphenylbenzidine} as hole transport layer(HTL), and Butyl-PBD(2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole) as emitting material layer(EML) and Alq3(8-Hydroxyquinoline, aluminum} as electron transport layer(ETL). Sample B is that we used TPD(N, N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine} as HTL and co-evaporated Butyl-PBD and Alq3 as EML. We investigated the characteristic of brightness and current-:voltage. The sample B that co-evaporated Butyl-PBD and Alq3 as EML improved characteristic of brightness and current-voltage than sample A. Maximum luminescence of sample B is $310cd/m^2$ and threshold voltage is 7V.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.598-602
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• 2004

Organic light entitling diode panel was fabricated using pulsed laser deposition (PLD) method Nd-YAG laser with Q-Switched and 355 nm pulse was used for the PLD. While TPD(N,N'-Di-[naphthaleny]-N, N'-diphenyl-benzidine) was used as a HTL(Hole transport layer), $Alq_3$(8-Hydroxyquinoline, Aluminum Salt) was used as EML/ETL(Emitting Layer/Electron Transport Layer) Organic pellet was fabricated and employed for the PLD method. The absorbances of the organic films were investigated and the measured absorbance values of TPD and $Alq_3$ films was 362 nm and 399 nm, respectively. The turn-on voltage of the OLED panel was 7.5 V and its luminance was $90\;cd/m^2$

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1015-1018
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• 2004

We investigate the influence of the New Electron Injection Layers (EIL) on the performance of the Alkali Metal Complex vapor-deposited Organic Light Emitting Diodes(OLED). Two different Alkali Metal Complex were used; Lithium Quinolate (Liq), and Sodium Quinolate (Naq). In all cases, $Alq_3$ was the Electron Transporting Layer (ETL). We measure and compare the current density-voltage (J-V) and luminance-voltage (L-V) characteristics. We concluded that the turn-on voltage, and luminance efficiency are controlled by the type of EIL material used. We show the longer life-time OLED with Alkali Metal Complex EIL than OLED with LiF EIL. And we show the Optimized Alkali Metal Complex thickness is 3nm. Existent LiF to because is inorganic material, there is trouble to do epitaxy into thin layers but regulates the thickness in case of Alkali Metal Complex matter characteristic that is easy be. Alkali Metal Complex also appeared by sensitive thing in thickness than LiF If utilize this material, It is thought much advantages may be at common use of OLED.

• 한국전기전자재료학회논문지
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• 제22권4호
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• pp.327-332
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• 2009

In the devices structure of ITO/N,N'-diphenyl-N,N' bis (3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) /tris (8-hydroxyquinoline)aluminum$(Alq_3)$electron-transport-layer(ETL)(2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP))/Al, we have studied the efficiency improvement of organic light-emitting diodes depending on the thickness variation of BCP using electron transport layer. The thickness of TPD and $Alq_3$ was manufactured 40 nm, 60 nm under a base pressure of $5{\times}10^{-6}$ Torr using at thermal evaporation, respectively. The TPD and $Alq_3$ layer were evaporated to be deposition rate of $2.5{\AA}/s$. And the BCP was evaporated to be a4 a deposition of $1.0{\AA}/s$. As the experimental results, we found that the luminous efficiency and the external quantum efficiency of the device is superior to others when thickness of BCP is 5 nm. Also, operating voltage is lowest. Compared to the ones from the devices without BCP layer, the luminous efficiency and the external quantum efficiency were improved by a factor of four hundred ninty and five hundred, respectively. And operating voltage is reduced to about 2 V.

• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.118-125
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• 2018

Herein we report on the selective synthesis and direct growth of nanostructures using an aqueous chemical growth route. Specifically, Al-doped ZnO (AZO) nanoflakes (NFs) are vertically grown on indium tin oxide (ITO) coated flexible polyethylene terephthalate (PET) sheets at low temperature and ambient environment. The morphological, optical, and electrical properties of the NFs are investigated as a function of the Al content. Furthermore, these AZO-NFs are integrated into perovskite solar devices as the electron transport layer (ETL) and the fabricated devices are tested for photovoltaic performance. It was determined that the doping of AZO-NFs significantly increases the performance metrics of the solar cells, mainly by increasing the short-circuit current of the devices. The observed enhancement is primarily attributed to the improved conductivity of the doped AZO-NF, which facilitates charge separation and reduces recombination. Further, our flexible solar cells fabricated through this low temperature process demonstrate an acceptable reproducibility and stability when exposed to a mechanical bending test.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.109-109
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• 2001

Purpose： To assess the feasibility of sequential administration of ferumoxides and mangafodi trisodium in the same imaging protocols. Method： Thirty patients underwent double-contrast enhanced MR imaging of liver usi ferumoxides (Fe-MRI) and mangafodipir trisodium (Mn-MRI) on 1.5T GE Horizon system. In twenty patients, Mn-MRI was immediately followed by Fe-MRI. In ten patients, Fe-MR was performed first, then Mn-MRI was performed immediately, In all cases, precontras T1-weighted in-phase and opposed-phase spoiled gradient echo (GRE) images an T2-weighted fast spin-echo images (TR 4000ms, TE 102ms, ETL 8-12) were obtained Fe-MRI was performed with FSE and steady state GRE (TE 10 msec, flip angle 30 sequences. Mn-MRI was performed with in-phase and opposed-phase spoiled GR sequences. The SNR changes after the use of each contrast agents were calculated.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.117-117
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• 2010

최근 10여년간 OLED는 급속한 기술발전으로 효율의 급속히 향상되어 100 lm 이상의 소자가 발표되고 있어, 디스플레이와 조명용 광원으로서의 응용 가능성이 증가하고 있다. 또한 에너지 및 환경의 중요성이 대두되며 효율은 점차 중요해 지고 있다. OLED의 효율 향상을 위해, 내부 양자효율이 25%인 형광 OLED를 대체할 수 있는, 인광 OLED가 대두되고 있다. 인광 OLED는 내부양자 효율이 형광 OLED에 비해 4배. 즉 100%의 내부양자 효율을 갖는다. 그러나 주로 사용되는 청색인광 물질인 FIrpic, Fir6 등의 수명이 짧다는 점과 색 좌표의 y값이 0.20 이상으로 하늘색 계열의 색특성을 보이는 등 여러 단점이 있다. 현제 이러한 단점을 보완하고자 하는 여러 연구가 진행되고 있다. 이에 본 연구에서는 다양한 호스트 물질을 사용, 도펀트 물질인 FIrpic을 도핑하여 청색인광의 효율을 높이고 수명을 증진시키고자 한다. 양극전극으로 RF 플라즈마 처리한 ITO를 사용하였으며, 진공증착방법을 사용하여 정공 주입층(HIL)으로 2-TNATA와 정공 수송층(HTL)으로 a-NPD을 증착하였으며, 전자 수송층(ETL)으로 Balq, 전자주입층(EIL)으로 LiF와 음극전극으로 Al을 증착하였다. 발광층(EML)에 사용되는 호스트 물질은 mCP, TCTA, CBP 등으로 다양화 하여 도펀트 물질인 FIrpic을 각각의 호스트 물질에 8 wt%으로 도핑하여 OLED 소자를 제작하였고, 전기 및 광학적 특성을 평가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.313-314
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• 2005

Organic light emitting diodes(OLEDs) are widely used as one of the information display techniques. We synthesized (1,10-phenanthroline)- (8-hydroxyquinoline) [Zn(Phen)q]. We studied the improvement of OLEDs properties using Zn(phen)q. The Ionization Potential(IP) and the Electron Affinity(EA) of Zn(phen)q investigated using cyclic voltammetry(CV). The IP, EA and Eg were 7.leV, 3.4eV and 3.7eV, respectively. The PL spectrum of Zn(phen)q was yellowish green as the wavelength of 535nm. In this study, we used Zn(phen)q as electron transporting layer(ETL) inserted between emitting layer(EML) and cathode. As a result, Zn(phen)q is useful as electron transporting layer to enhance the performance of OLEDs.

• 한국정보과학회논문지:데이타베이스
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• 제28권1호
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• pp.48-56
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• 2001

XML은 여러 분야에서 다양한 타입의 데이터를 효과적으로 관리하기 위한 표준으로 사용되고 있다. 이러한 XML의 한 응용으로서 데이터베이스 시스템, 파일 시스템, OLTP시스템, OLAP시스템, 데이터웨어하우징을 위한 ETL 시스템, 데이터마이닝 시스템 등을 포함하는 다양한 타입의 데이터 처리 시스템 사이에서 메타데이터를 교환하기 위하여 XML을 이용하여 메타데이터를 표준화하는 것이다. 본 연구는 MDC(MetaData Coalition)에 제안한 일반적인 데이터 처리 시스템을 위한 메타데이터 교환 스펙인 MDIS(Metadata Interchange Specification)를 따르도록 설계한 관계형 데이터베이스 시스템의 메타데이터 교환을 위한 사양으로서 R-MDIS(MetaData Interchange Specification for RDBs) 모델을 제안하고 이에 따라 표현된 자료를 상호 데이터베이스 시스템 사이에서 교환할 수 있는 Export 함수와 Import 함수를 포함하는 번역기를 개발한다. 이 번역기는 메타데이터의 일관성을 유지하면서도 메타데이터의 양방향 흐름을 지원할 수 있도록 하는 정보를 포함하고 있다. 본 연구는 구체적인 관계형 데이터베이스 시스템에서의 메타데이터 교환을 위한 실제적인 번역기를 구현함으로써 다양한 종류의 데이터 처리 시스템들 사이에서 메타데이터 불일치 문제를 해결할 수 있는 근거를 제시하였다. 둘째, XML을 이용하여 메타데이터 교환 사양을 설정함으로서 구도화된 데이터나 구조화되지 않은 데이터 모두에 대하여 일관된 방법으로 데이터 교환이 가능하도록 하여 효율적인 정보 교환을 할 수 있다는 것을 보여 주었다. 셋째, 본 연구에서 개발한 번역기는 메타데이터 교환에 의해 데이터들을 공유하게 함으로서 효율적으로 관리하지 못하던 데이터들을 효율적으로 사용할 수 있게 함으로서 데이터 관리 문제에 해결책이 될 것이다.