https://pubs.kist.re.kr/handle/123456789/75366 2026-02-28T11:32:24Z 2026-02-28T11:32:24Z Choi, Yoon-Young Kang, Seong Jun Kim, Han-Ki Choi, Won Mook Na, Seok-In https://pubs.kist.re.kr/handle/201004/129702 2024-04-25T14:09:40Z 2012-01-01T00:00:00Z

Title: Multilayer graphene films as transparent electrodes for organic photovoltaic devices Authors: Choi, Yoon-Young; Kang, Seong Jun; Kim, Han-Ki; Choi, Won Mook; Na, Seok-In Abstract: We have fabricated ITO-free organic solar cells (OSCs) based on multilayer graphene (MLG) electrodes. MLG electrodes with high transparency (similar to 84.2%) and low sheet resistance (similar to 374 +/- 3 Omega/square) were obtained on glass substrates using chemical vapor deposition and a multi-transfer process. The OSCs fabricated on MLG electrodes had an open circuit voltage of 0.52 V. a short circuit current of 6.90 mA/cm(2), a fill factor of 32.6%, and a power conversion efficiency of 1.17%. The performance of the OSCs fabricated on transparent MLG electrode was not comparable to that of OSCs fabricated on ITO electrodes; cost-effective MLG electrodes are a viable alternative to sputter-grown ITO electrodes for cost-efficient and flexible OSCs. (C) 2011 Elsevier B.V. All rights reserved.

2012-01-01T00:00:00Z Kim, Yeon Seok Le Thuy Linh Park, Eun Seok Chin, Sungmin Bae, Gwi-Nam Jurng, Jongsoo https://pubs.kist.re.kr/handle/201004/129701 2024-04-25T14:09:38Z 2012-01-01T00:00:00Z

Title: Antibacterial performance of TiO2 ultrafine nanopowder synthesized by a chemical vapor condensation method: Effect of synthesis temperature and precursor vapor concentration Authors: Kim, Yeon Seok; Le Thuy Linh; Park, Eun Seok; Chin, Sungmin; Bae, Gwi-Nam; Jurng, Jongsoo Abstract: TiO2 nanoparticles were synthesized using a chemical vapor condensation (CVC) method, and their physicochemical properties were characterized to optimize the synthesis conditions for antibacterial activity. The antibacterial activities of CVC-TiO2 nanoparticles and commercialized TiO2 nanoparticles (P25, Deggusa) were investigated according to UV exposure time and amount of photocatalyst. We found that the specific surface area and the crystallinity of CVC-TiO2 nanoparticles were varied depending on synthesis temperature and precursor vapor concentration. As a result, the CVC-TiO2 nanoparticles showed a higher specific surface area and better crystallinity than that of P25TiO(2). More importantly, CVC-TiO2 nanoparticles generated a larger amount of hydroxyl radicals than P25TiO(2). Consequently CVC-TiO2 nanoparticles were more effective as an antibacterial photocatalyst than P25TiO(2) under irradiation with UV light. Based-on these results, the optimum synthetic conditions of CVC-TiO2 nanoparticles for bactericidal effect were found. (C) 2011 Elsevier B.V. All rights reserved.

2012-01-01T00:00:00Z Yoon, Jong Moon Jeong, Hu Young Hong, Sung Hoon Yin, You Moon, Hyoung Seok Jeong, Seong-Jun Han, Jun Hee Kim, Yong In Kim, Yong Tae Lee, Heon Kim, Sang Ouk Lee, Jeong Yong https://pubs.kist.re.kr/handle/201004/129700 2024-04-25T14:09:36Z 2012-01-01T00:00:00Z

Title: Large-area, scalable fabrication of conical TiN/GST/TiN nanoarray for low-power phase change memory Authors: Yoon, Jong Moon; Jeong, Hu Young; Hong, Sung Hoon; Yin, You; Moon, Hyoung Seok; Jeong, Seong-Jun; Han, Jun Hee; Kim, Yong In; Kim, Yong Tae; Lee, Heon; Kim, Sang Ouk; Lee, Jeong Yong Abstract: We demonstrate the fabrication and phase change memory performance of a conical TiN/Ge2Sb2Te5 (GST)/TiN nanoarray prepared via block copolymer lithography and straightforward two-step etching. The created 30 nm scale phase change memory cell (aerial array density: similar to 207 Gbit inch(-2)) showed a threshold switching voltage of 1.1 V, a value compatible to conventional phase change memory cells. More significantly, the cell could be amorphized by a reset pulse of 1.8 V height and 100 ns width, where the reset current was 100 mu A. Such a low reset current, presumably caused by nanoscale small cell dimension, is greatly beneficial for low power consumption device operation. Reversibly, the set operation was accomplished by crystallization with a set pulse of 1.2 V height, 100 ns width, and 100 ns trailing. This work provides a significant step for low power consumption and ultra-high density storage based on phase change materials.

2012-01-01T00:00:00Z Jaworski, Jacek A. Fleury, Eric https://pubs.kist.re.kr/handle/201004/129699 2024-04-25T14:09:34Z 2012-01-01T00:00:00Z

Title: Sub-Micrometer Particles Produced by a Low-Powered AC Electric Arc in Liquids Authors: Jaworski, Jacek A.; Fleury, Eric Abstract: The article presents the report of the production of composites of sub-micrometer metal particles in matrix consisted of the metal compounds by means of an AC electric arc in water and paraffin solutions using electrodes carbon metal and metal metal (metal: Ni, Fe, Co, Cu). The advantage of this method is the low electric power (from 5 to 10 W) needed in comparison to standard DC arc-discharge methods (0.8 to 3 kW). This method enables the production of particles from conductive material also in wide range of temperature and in solvent which could be either transparent to light or opaque. Moreover the solvent can be electrolyte or insulating liquid. The microstructure of the composite layer was investigated by scanning electron microscopy (SEM), Electron Probe Microanalysis (EPMA) and X-ray. During particles production in water metal oxides were created. Additionally using cobalt copper, nickel copper as couple electrodes, insoluble in water copper (II) hydroxide crystal grains were created additionally which crystals shape was depended on transition metal. For iron copper couple electrodes system the copper (II) hydroxide was not formed. Experiments with sequence production of Ni and Fe particles with C electrode assisting in molten paraffin let to obtain both Ni and Fe. particles surrounded by paraffin. After solidification the material was insulator but if locally magnetic field influenced on the liquid solution in that place after solidification a new composite was created which was electric current conductor with resistivity around 0.1 Omega . m, was attracted by magnetic field and presented magneto resistance around 0.4% in changing magnetic field in a range 150 mT. After mixing the concentrated paraffin with normal paraffin resistivity of the mixture increased and it became photosensitive and created small voltage under light influence.

2012-01-01T00:00:00Z