• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.927-931
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• 2010

Recently, high luminance and high efficiency were realized in OLED with multilayer structure including emitting materials such as metal-chelate complexes. We synthesized a new luminescent material, namely, [2-(2-hydroxyphenyl)quinoline] (Zn(HPB)q) which has low molecular compound and emitted in yellowish green region. The ionization potential(IP) and electron affinity(EA) of Zn(HPB)q were measured by cyclic-voltammetry(CV). As a result, IP and EA of Zn(HPB)q were calculated 6.8 eV and 3.5 eV, respectively. We fabricated the devices and observed the possibility of Zn(HPB)q as electron transporting layer. We have obtained an improvement of luminance and decrease of turn-on voltage using Zn(HPB)q as electron transporting layer.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.125-126
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• 2000

We report the use of fluorene based copolymers containing quinoline(POF66, PIF66) and pyridine(PFPV) units as electron transporting polymers for multi-layered LEDs. Double-layer device structure combining PIF66 as electron-transporting layer with the emissive MEHPPV showed a maximum quantum efficiency of 0.03%, which is 30 fold increased compared with ITO/MEHPPV/Al single-layer device. PFPV layer increased the quantum efficiency up to 0.1% in the device structure of ITO/(P-3:PVK)/PFPV/Al. The ETL with the electron deficient moiety improved the LED performance by the characteristics of electron transporting as well as hole blocking between emissive layer and metal cathode.

• Electronic Materials Letters
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• v.14 no.6
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• pp.657-668
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• 2018

Organic-inorganic hybrid lead halide perovskites have been extensively investigated for various optoelectronic applications. Particularly, owing to their ability to form highly crystalline and homogeneous films utilizing low-temperature solution processes (< $150^{\circ}C$), perovskites have become promising photoactive materials for realizing high-performance flexible solar cells. However, the current use of mesoporous $TiO_2$ scaff olds, which require high-temperature sintering processes (> $400^{\circ}C$), has limited the fabrication of perovskite solar cells on flexible substrates. Therefore, the development of a low-temperature processable charge-transporting layer has emerged as an urgent task for achieving flexible perovskite solar cells. This review summarizes the recent progress in low-temperature processable electron- and hole-transporting layer materials, which contribute to improved device performance in flexible perovskite solar cells.

• Fire Science and Engineering
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• v.30 no.6
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• pp.23-30
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• 2016

This study analyzed the characteristics of chemical accidents, including the accidents occurring each year according to status, type of accident, accident cause for chemical substance transporting accidents. The major aim of this study was to provide information on the chemical accidents that occurred involving chemical substance transporting accidents from 2013 to July - 2016. The total incidence of chemical transporting accidents was 77 cases; 74 cases occurred by the spill & leakage type. The main cause of the accidents analyzed was traffic accidents (41 cases). Forty-six accidents were related to hazardous chemical substances. Among the 46 hazardous chemical substances involved in transporting chemical accidents, 46% of the accident substances were hydrogen chloride. For the prevention and response to accidents occurring during the transportation of chemicals, it is necessary to complement the precautions for chemical accidents caused by transportation accidents and chemical spills and leaks of chemicals. In addition, when the chemical transport of an accident occurs, it is necessary to apply a chemical transport safety system for chemical transfer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4267-4275
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• 2015

Prefabricated houses are fabricated at the factory for approximately 60 to 80% of the entire construction process, and assembled in the field. In the process of transporting and lifting, internal and external finishes of the unit module are concerned about damages. The purpose of this study is to improve the fixing equipment by analyzing load behavior. The improved fixing equipment would minimize the deformation of internal and external finishes. In order to develop the improved fixing equipment, transporting load on the fixing equipment is analyzed using Monte Carlo simulations, and structural performance is verified by the non-linear finite element analysis. Statistical analysis shows load distribution of unit module is similar with extreme value distribution. Based on the statistical analysis and Monte Carlo simulation, the maximum transporting load is 28.9kN and 95% confidence interval of transporting load is -1.22kN to 9.5kN. The nonlinear structural analysis shows improved fixing equipment is not destructed to the limit load of 35.3kN and withstands the load-bearing in the 95% confidence interval of transporting load.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.53-56
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• 2002

The effect of $\alpha$-septithiophene (${\alpha}-7T$) layers on the organic light emitting diode(OLED) was studied. The ${\alpha}-7T$ was used for a buffer layer in OLED. Hole injection was investigated and improved emission efficiency. The OLEDs structure can be described as indium tin oxide(ITO)/ buffer layer / hole transporting layer / emitting layer / electron transporting layer / LiF / Al. The hole transporting layer were composed of N,N-diphenyl-N,N-di(3-methylphenyl)-1,1-biphenyl-4,4-diamine(TPD), and N,N-di(naphthalene-1-ly)-N,N-diphenyl-benzidine( ${\alpha}$-NPD). The emitting layer, and electron transporting layer consist of tris(8-hydroxyquinolinato) aluminum($Alq_3$). All organic layer were deposited at a background pressure of less than $10^{-6}$ torr using ultra high vacuum (UHV) system. The ${\alpha}-7T$ layer can substitute the hole blocking layer, and improve hole injection properties.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.662-667
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• 2009

The research are performed to check the characteristics of the ice slurry transport system for the district cooling. The system are installed at the 1st floored building which is as large as the $1204\;m^2$ ($86\;m{\times}14\;m$), and the pumping power and branching characteristics are measured by transporting of the ice slurry. The ice slurry transporting pipe is as long as 200 m. For the same cooling load, the higher IPF is, the lower the transporting flow rate and the pumping power are. But when the IPF is higher than 15%, no less decrease of the pumping power does happen. For the branching characteristics, through the branch pipe where the flow resistance is higher, the higher IPF is measured. A little higher IPF is measured at the thermal expansion branch.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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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.

• Current Photovoltaic Research
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• v.8 no.2
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• pp.60-65
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• 2020

In perovskite solar cells with planar heterojunction configuration, selection of proper charge-transporting layers is very important to achieve stable and efficient device. Here, we developed solution processible Cu doped NiO_x (Cu:NiO_x) thin film as a hole-transporting layer (HTL) in p-i-n structured methylammonium lead trihalide (MAPbI₃) perovskite solar cell. The transmittance and thickness of NiO_x HTL is optimized by control the spin-coating rate and Cu is additionally doped to improve the surface morphology of undoped NiO_x thin film and hole-extraction properties. Consequently, a perovskite solar cell containing Cu:NiO_x HTL with optimal doping ratio of Cu exhibits a power conversion efficiency of 14.6%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.436-437
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• 2007

Organic light-emitting diodes (OLEDs) were fabricated with the electron dominant complex, 4,7-diphenyl-1, 10-phenanthroline (Bphen) into the traditional electron transporting material of tris (S-hydroxyquinoline) aluminum $(Alq_3)$, neat $Alq_3$ and Bphen as electron-transporting layers (ETLs), respectively. Use of the Bphen material results in efficient electron injection and transport, allowing for high luminous efficiency devices. The devices with neat $Alq_3$(Device1), 1:1 mixed $Alq_3$ : Bphen(Device2), and Bphen(Device3) have efficiency of 15.3cd/A, 16.9cd/A, 20.9cd/A, respectively, at $20\;mA/cm^2$. The efficiency characteristic of device with Bphen is best, but the device that is satisfied high efficiency and stability at once is observed in Device2.