• 한국전기전자재료학회논문지
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• 제24권1호
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• pp.70-75
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• 2011

We introduced nanoscale interfacial layers between the PV layer and the cathode in poly (3-hexylthiophene):methanofullerene bulk-heterojunction polymer photovoltaic (PV) cells. The nanoscale double interfacial layers were made of ultrathin poly (oxyethylenetridecylether) surfactant and low-work-function alloy-metal of Al:Li layers. It was found that the nanoscale interfacial layers increase the photovoltaic performance, i.e., increasing short-circuit current density and fill factor with improved device stability. For PV cells with the nanoscale double interfacial layers, an increase in power conversion efficiency of $4.18{\pm}0.24%$ was achieved, compared to that of the control devices ($3.89{\pm}0.08%$) without the double interfacial layers.

• 한국광학회지
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• 제18권3호
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• pp.226-231
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• 2007

본 논문에서는 이중 금속선으로 이루어진 다양한 곡선형 도파로를 고려하고 이 구조들에서 전파하는 모드의 특성을 수치해석적으로 분석하였다. 이중 금속선들 간의 간격과 내부 유전체의 굴절률 변화에 따라 곡선형 도파로의 최적 반경과 최소손실의 경향을 조사하였으며, 그 결과 이중 금속선 구조가 단일 금속선 구조보다 전파특성이 좋은 최적 구조가 존재함을 확인하였다.

• KIEAE Journal
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• 제2권3호
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• pp.39-45
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• 2002

Double facades are built to allow natural ventilation in high rise buildings and buildings with high outside noise level. In high rise Buildings the gains in summer can be reduced by sufficient sun protection devices placed outside the rooms in the ventilated space between the inner and outer facade. To evaluate the energetic performance, three buildings with double facade were monitored for at least one year (Siemens Building in Dortmund/Germany, Victoria Insurance Company in Duesseldorf/Germany and RWE Tower in Essen/Germany). The results document the indoor climate, the boundary conditions for further planning and the possibilities for high rise buildings without or with little cooling facilities.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.97-98
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• 2006

High current behaviors of the grounded gate extended drain N-type metal-oxide-semiconductor field effects transistor (GG_EDNMOS) electro-static discharge (ESD) protection devices are analyzed. Simulation based contour analyses reveal that combination of BJT operation and deep electron channeling induced by high electron injection gives rise to the 2-nd on-state. Thus, the deep electron channel formation needs to be prevented in order to realize stable and robust ESD protection performance. Based on our analyses, general methodology to avoid the double snapback and to realize stable ESD protection is to be discussed.

• ETRI Journal
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• 제44권1호
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• pp.147-154
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• 2022

We demonstrate a new double-layer structure for stretchable interconnects, where the top surface of a serpentine polyimide support is coated with a thin eutectic gallium-indium liquid metal layer. Because the liquid metal layer is constantly fixed on the solid serpentine body in this liquid-on-solid structure, the overall stretching is accomplished by widening the solid frame itself, with little variation in the total length and cross-sectional area of the current path. Therefore, we can achieve both invariant resistance and infinite fatigue life by combining the stretchable configuration of the underlying body with the freely deformable nature of the top liquid conductor. Further, we fabricated various types of double-layer interconnects as narrow as 10 ㎛ using the roll-painting and lift-off patterning technique based on conventional photolithography and quantitatively validated their beneficial properties. The new interconnecting structure is expected to be widely used in applications requiring high-performance and high-density stretchable circuits owing to its superior reliability and capability to be monolithically integrated with thin-film devices.

• 한국진공학회지
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• 제5권3호
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• pp.175-180
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• 1996

Double conductance method is proposed as an effectvie way to measure real outgassing rates of materials regardless of their adsorbing power. The real outgassing rate and the sticking coefficient of the CFC (carbon fiber composite) which is used widely as the material for armor plates infusion experiment devices were obtained by adopting this method. At $40^{\circ}C$ the real ougassing rate was $Pa, m^3/s.m^2$(in $N_2$ equivalent), which was higher than 5 times the measured one, and the sticking coefficient was about 0.018($H_2O\; and \;H_2$ were the main residual gases).

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.460-463
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• 1999

A new multi-step voltage source inverter is proposed in this paper. The proposed scheme is composed of the double-connected 12-step inverter with an auxiliary circuit. The auxiliary circuit includes two voltage dividing capacitors, two switching devices and a low KVA autotransformer. The resultant system is shown to be a 24-step inverter suitable for large scale SVC applications in which the PWM method can not be employed. The design parameters are derived from the analysis of voltages and currents by means of switching functions. The simulation results verify the proposed concept.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1993년도 추계학술대회논문집; 반도아카데미, 26 Nov. 1993
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• pp.157-161
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• 1993

Optical devices and electronic equipments used in the laboratory of the synchrotron light source building of the accelerator have stringent vibration limits. In order to control the vibration of the building structure and HVAC systems which are main vibration sources are evaluated using experimental modal analysis. Double anti-vibration system is used for the HVAC system and results show that the double anti-vibration system reduces the vibrations of the building to acceptable levels.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.278-278
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• 2016

Solution-processed metal-oxide semiconductors have been considered as the next generation semiconducting materials for transparent and flexible electronics due to their high electrical performance. Moreover, since the oxide semiconductors show high sensitivity to light illumination and possess persistent photoconductivity (PPC), these properties can be utilized in realizing optical memory devices, which can transport information much faster than the electrons. In previous works, metal-oxide semiconductors are utilized as a memory device by using the light (i.e. illumination does the "writing", no-gate bias recovery the "reading" operations) [1]. The key issues for realizing the optical memory devices is to have high photoconductivity and a long life time of free electrons in the oxide semiconductors. However, mono-layered indium-zinc-oxide (IZO) and mono-layered indium-gallium-zinc-oxide (IGZO) have limited photoconductivity and relaxation time of 570 nA, 122 sec, 190 nA and 53 sec, respectively. Here, we boosted up the photoconductivity and relaxation time using a double-layered IZO/IGZO active layer structure. Solution-processed IZO (top) and IGZO (bottom) layers are prepared on a Si/SiO2 wafer and we utilized the conventional thermal annealing method. To investigate the photoconductivity and relaxation time, we exposed 9 mW/cm2 intensity light for 30 sec and the decaying behaviors were evaluated. It was found that the double-layered IZO/IGZO showed high photoconductivity and relaxation time of 28 uA and 1048 sec.

• 한국재료학회지
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• 제18권4호
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• pp.199-203
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• 2008

High-efficiency phosphorescent organic light emitting diodes using TCTA-TAZ as a double host and $Ir(ppy)_3$ as a dopant were fabricated and their electro-luminescence properties were evaluated. The fabricated devices have the multi-layered organic structure of 2-TNATA/NPB/(TCTA-TAZ) : $Ir(ppy)_3$/BCP/SFC137 between an anode of ITO and a cathode of LiF/AL. In the device structure, 2-TNATA[4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] and NPB[N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] were used as a hole injection layer and a hole transport layer, respectively. BCP [2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline] was introduced as a hole blocking layer and an electron transport layer, respectively. TCTA [4,4',4"-tris(N-carbazolyl)-triphenylamine] and TAZ [3-phenyl-4-(1-naphthyl)-5-phenyl-1,2,4-triazole] were sequentially deposited, forming a double host doped with $Ir(ppy)_3$ in the [TCTA-TAZ] : $Ir(ppy)_3$ region. Among devices with different thickness combinations of TCTA ($50\;{\AA}-200\;{\AA}$) and TAZ ($100\;{\AA}-250\;{\AA}$) within the confines of the total host thickness of $300\;{\AA}$ and an $Ir(ppy)_3$-doping concentration of 7%, the best electroluminescence characteristics were obtained in a device with $100\;{\AA}$-think TCTA and $200\;{\AA}$-thick TAZ. The $Ir(ppy)_3$ concentration in the doping range of 4%-10% in devices with an emissive layer of [TCTA ($100\;{\AA}$)-TAZ ($200\;{\AA}$)] : $Ir(ppy)_3$ gave rise to little difference in the luminance and current efficiency.