• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.7
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• pp.641-646
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• 2005

To fabricate a single layer white organic light emitting diode (OLED), a novel non-conjugated blue emitting material PPPMA-co-DTPM copolymer was synthesized containing a perylene moiety unit with hole transporting and blue emitting ability and a triazine moiety unit with electron transporting ability. The devices were fabricated using PPPMA-co-DTPM $(PPPMA[70\;wt\%]:DTPM[30\;wt\%])$ copolymer by varying the doping concentrations of each red, green and blue fluorescent dye, by molecular-dispersing into Toluene solvent with spin coating method. In case of ITO/PPPMA-co-DTPM:TPB$(3\;mol\%):C6(0.04\;mol\%):NR(0.015\;mol\%)/Al$ structure, as they were molecular-dispersing into 30 mg/ml Toluene solvent, nearly-pure white light was obtained both (0.325, 0.339) in the CIE coordinates at 18 V and (0.335, 0.345) at 15 V. The turn-on voltage was 3 V, the light-emitting turn-on voltage was 4 V, and the maximum external quantum efficiency was $0.667\%$ at 24.5 V. Also, in case of using 40 mg/ml Toluene solvent, the CIE coordinate was (0.345, 0.342) at 20 V.

• Korean Journal of Materials Research
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• v.32 no.5
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• pp.237-242
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• 2022

Designing and producing a low-cost, high-current-density electrode with good electrocatalytic activity for the oxygen evolution reaction (OER) is still a major challenge for the industrial hydrogen energy economy. In this study, nanostructured Fe-doped CuCo(OH)₂ was discovered to be a precedent electrocatalyst for OER with low overpotential, low Tafel slope, good durability, and high electrochemically active surface sites at reduced mass loadings. Fe-doped CuCo(OH)₂ nanosheets are made using a hydrothermal synthesis process. These nanosheets are clumped together to form a highly open hierarchical structure. When used as an electrocatalyst, the Fe-doped CuCo(OH)₂ nanosheets required an overpotential of 260 mV to reach a current density of 50 mA cm^-2. Also, it showed a small Tafel slope of 72.9 mV dec^-1, and superior stability while catalyzing the generation of O₂ continuously for 20 hours. The Fe-doped CuCo(OH)₂ was found to have a large number of active sites which provide hierarchical and stable transfer routes for both electrolyte ions and electrons, resulting in exceptional OER performance.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.162-162
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• 2009

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1093-1095
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• 2006

An orange-emitting phosphor for inorganic electroluminescent device has been studied. Cu and Cl were co-doped in Mn-doped ZnS for a high-performing phosphor. The effect of $Mn^{2+}-doping$ concentration as well as $Mg^{2+}-sensitizer$ addition on the luminescence characteristics has been investigated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.107-107
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• 2005

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.5
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• pp.813-817
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• 1987

High value sheet resistance (Rs' 1K-33K\ulcorner/) polysilicon resistors were fabricated using double ion implantation with boron as the major dopant and phosphorus compensation. It is observed that Rs sensitivity to the net doping concentration is decreased by one order of magnitude compared to the conventional (boron implanted)polysilicon resistors. The temperature co-efficient of resistance (TCR) measured between 25\ulcorner and 125\ulcorner shows equivalent values to those of non-compensated resistors for the same Rs. A qualitative electrical conductiion mechanism for compensated polysilicon resistor is proposed, based on the existing grain boundary charge trapping theory.

• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.192-192
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• 2016

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.579-583
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• 1998

Silicide layer structures, agglomeration of silicide layers, and dopant redistributions for the Co/Ti bilayer sputter-deposited on the P-doped polycrystalline Si substrate and subjected to rapid thermal annealing were investigated and compared with those on the single Si substrate. The $CoSi_2$ phase transition temperature is higher and agglomeration of the silicide layer occurs more severely for the Co/Ti bilayer on the doped polycrystalline Si substrate than on the single Si substrate. Also, dopant loss by outdiffusion is much more significant on the doped polycrystalline Si substrate than on the single Si substrate. All of these differences are attributed to the grain boundary diffusion and heavier doping concentration in the polycrystalline Si. The layer structure after silicidation annealing of Co/ Tildoped - polycrystalline Si is polycrystalline CoSi,/polycrystalline Si, while that of Co/TiI( 100) Si is Co- Ti- Si/epi- CoSi,/(lOO) Si.

• Korean Journal of Materials Research
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• v.1 no.1
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• pp.23-28
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• 1991

The resistivity of polycrystalline silicon film deposited by low pressure chemical vapor deposition and doped by arsenic Implantation has been investigated as a function of dopant concentration and testing temperature ranging from $25^{\circ}C$ to $105^{\circ}C$ . The resistivity vs. doping concentration curve had a peak point with highest activation energy with respect to the dependence of the resistivity on temperature. We showed that $O_2$ plasma anneal followed by heat-treatment in $N_2$ ambient was able to recover the resistivity degraded by the plasma deposited passivation layers.

• Advances in materials Research
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• v.1 no.1
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• pp.75-81
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• 2012

In this work, the Co-doped ZnO rods were prepared by the hydrothermal method. The size of these rods can be changed from micro-size to nano-size by using different solutions during the preparation. The results of transmission electron microscopy (TEM) and selected area electron diffraction (SAED) showed that the as-prepared nano-sized Co-doped rods have single-crystal structure. The polarized Raman experiments were presented on an individual micro-sized Co-doped ZnO rod in the $X(YY)\vec{X}$, $X(ZY)\vec{X}$ and $X(ZZ)\vec{X}$ configurations, the results of polarized Raman indicated that these rods are crystallized and their growth direction is parallel to c-axis.