• Nuclear Engineering and Technology
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• 제5권2호
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• pp.94-102
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• 1973

원주상 재결합 영역에 있어서 전리함의 포화특성을 이론적으로 검토하고, 보론 피복 원통형 전리한을 설계, 제작하여 내부에 질소 또는 헬륨을 760mmHg와 380mmHg로 충전시켜서 실험적임 측정을 하였다. 해석적임 방법으로 도출한 collection efficiency의 식은 실험결과와 잘 일치하였다. 이 결과를 이용하면 보론을 피복한 전리함의 포화특성을 실험적인 측정 업이 설계치에 의한 이론적인 계산만으로 예측할 수 있다.

• 천문학회보
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• 제41권2호
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• pp.29.4-29.4
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• 2016

The relations between star formation and properties of molecular clouds are studied based on a sample of star forming regions in the Galactic Plane. Sources were selected by having radio recombination lines to provide identification of associated molecular clouds and dense clumps. Radio continuum and mid-infrared emission were used to determine star formation rates, while 13CO and submillimeter dust continuum emission were used to obtain masses of molecular and dense gas, respectively. We test whether total molecular gas or dense gas provides the best predictor of star formation rate. We also test two specific theoretical models, one relying on the molecular mass divided by the free-fall time, the other using the free-fall time divided by the crossing time. Neither is supported by the data. The data are also compared to those from nearby star forming regions and extragalactic data. The star formation "efficiency," defined as star formation rate divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all the molecular gas.

• 한국세라믹학회지
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• 제22권4호
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• pp.9-14
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• 1985

The quantum efficiency vs. wavelength curves with different reducing treatments for the 99.99% and 98.5% $TiO_2$ ceramic electrodes have been analyzed according to the Schottky barrier model of the semiconductor-elect-rolyte interface, The model allows the main physical parameters governing the photoelectrochemical properties of the semicon-ductor to be determined. According to these data the impurity ions as three valence state ($Fe^{3+})$ in the $TiO_2$ raw materials have great influence on the photoresponse and the $TiO_2$ ceramic electrodes show much lower quantum efficiency than the $TiO_2$ single crystal due to existence of the recombination centers.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1056-1058
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• 2005

Electrical and optical characteristics of MEH-PPV-based PLEDs with the LiF anode interfacial layer were investigated. The maximum luminance efficiency of the device with a LiF anode interfacial layer of 1-nm-thick was 3.0 lm/W, which is higher than 1.97 lm/W of the device without a LiF layer. By inserting LiF, excess injected holes from ITO anode can be blocked and hence the recombination ratio of electrons and holes can be increased in the emitting layer to improve device efficiency.

• Journal of Information Display
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• 제10권3호
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• pp.107-110
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• 2009

Efficient deep-blue organic light-emitting diodes were demonstrated using 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl doped in double-emission layers (D-EMLs). The D-EML system, which consists of 2-methyl-9,10-di(2-naphthyl)anthracene and 1,4-(dinaphthalen-2-yl)-naphthalene as blue hosts, was employed to broaden the recombination zone and to ensure the good confinement of the holes and electrons. The optimized device showed a peak current efficiency of 4.47 cd/A, a peak external quantum efficiency of 4.09%, and Commission Internationale de L'Eclairage coordinates of (0.16, 0.10).

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권9호
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• pp.400-406
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• 2003

Efficient electrodes are devised for organic luminescent device(OLED). ITO electrode is treated with $O_2$ plasma. In order to inject hole efficiently, there is proposed the shape of anode that inserted plasma polymerized films as buffer layer between anode and organic layer using thiophene monomer. In the case of device inserted the buffer layer by using the plasma polymerization after $O_2$ plasma processing for ITO transparent electrode, since it forms the stable interface and reduce the moving speed of hole, the recombination of hole and electronic are made in the emitting layer. Therefore it realized the device capability of two times in the aspect of luminous efficiency than the device which do not be inserted the buffer layer. Experiments are limited to the device that has the structure of TPD/$AIq_3$, however, the aforementioned electrodes can similarly applied to the organic luminous device and the Polymer luminous device.

• Rapid Communication in Photoscience
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• 제2권3호
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• pp.85-88
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• 2013

Silica nanoparticles were synthesized with various silane coupling agents to make specific pathway of electrons and anti-recombination system when solidifying liquid electrolytes. In this study, we used an appropriate method of synthesis for activated silica nanoparticles and silane coupling agents with 3-(triethoxysilyl)propionitrile, Trimethoxy[3-(methylamino)propyl]silane, Triethoxyoctylsilane, and octadecyltrimethoxy silane. Dye-sensitized solar cells using solidified electrolytes with silica nanoparticles exhibit comparatively excellent efficiency, ranging from 2.3 to 7.0% under similar conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.192-195
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• 2009

We developed highly efficient blue PHOLEDs with reduced roll-off by using a mixed host structure. The balanced charge carrier injection and the distributed recombination zone within emissive layer resulted in a highly stable efficiency roll-off with quantum efficiencies of 20.1 and 18.1 % at a luminance of 1000 and 10000 cd/$m^2$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.184-187
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• 2009

In this paper, we study effect of charge balance on performance of blue phosphorescent organic light emitting diodes (OLEDs). Charge balance determines the location of recombination zone in the OLEDs. By tuning the charge balance in iridium (III) bis[(4,6-difluorophenyl)-pyridinate-N,C2']picolinate (FIrpic) based blue phosphorescent organic light-emitting devices (PHOLEDs) with a high mobility and high triplet energy electron transporting material, we were able to achieve a high current efficiency of 60 cd/A which is a 3X improvement over previous devices with 3,5'-N,N'-dicarbazole-benzene (mCP) host.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2491-2494
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• 2013

The effect of additives in an electrolyte solution on the conversion efficiency of a dye sensitized solar cell was investigated. A density functional theory (DFT) method was used to examine the physical and chemical properties of nitrogen-containing additives adsorbed on a $TiO_2$ surface. Our results show that additives which cause lower partial charges, higher Fermi level shifts, and greater adsorption energies tend to improve the performance of DSSCs. Steric effects that prevent energy losses due to electron recombination were also found to have a positive effect on the conversion efficiency. In this work, 3-amino-5-methylthio-1H-1,2,4-triazole (AMT) has been suggested as a better additive than the most popular additive, TBP, and verified with experiments.