• 한국군사과학기술학회지
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• 제13권4호
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• pp.699-707
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• 2010

Electric-field-induced electron emission from the three kinds of $Pb(Zr_{0.56}Ti_{0.44})O_3$ ferroelectric cathodes with different electrode structure has been investigated. Regardless of the electrode structures, a threshold field of the each cathode was 2.5-2.6kV/mm, which is 3 times higher than the coercive field of $Pb(Zr_{0.56}Ti_{0.44})O_3$ material. Although the waveform of the electron currents was affected by the structure of the electrode, no significant difference for the emission properties such as the peak current and the pulse width was observed from the three kinds of the cathodes. However, the current density of the cathode was dependent on the electrode structure. From the simulation of electric field distribution, the surface flashover, and the injury region of the cathode surface, it was proved that the prime electrons were initiated at the electrode-ceramic-vacuum triple point by field emission and the emission currents were strongly enhanced by the surface plasma.

• 반도체디스플레이기술학회지
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• 제10권2호
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• pp.115-119
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• 2011

A tip-type carbon nanotube(CNT)-based field emitter was studied to consider it as electron source for micro-focused x-ray tube. The CNT was grown directly on a metal (tungsten) substrate by using an inductively coupled plasma-chemical vapor deposition (ICP-CVD) method. Prior to CNT growth, the metal substrate was etched to have various tip angles from $10^{\circ}$ to $180^{\circ}C$ (flat-type). The morphologies and microstructures of all the grown CNTs were analyzed via field-emission SEM. Furthermore, the effects of substrate tip-angles on the emission properties of CNT-based field emitters were characterized to estimate the maximum current density, the turn-on voltage, and the spatial distribution of electron beams. Prolonged long-term stability testing of the CNT emitters was also performed. All the experiment results obtained from this study indicated why a tip-type CNT emitter, compared with a flat-type CNT emitter, would be more desirable for a micro-focused x-ray system, in terms of the emission current level, the focused beam area, and the emission stability.

• Carbon letters
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• 제15권3호
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• pp.214-217
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• 2014

A filtration-taping method was demonstrated to fabricate carbon nanotube (CNT) emitters. This method shows many good features, including high mechanical adhesion, good electrical contact, low temperature, organic-free, low cost, large size, and suitability for various CNT materials and substrates. These good features promise an advanced field emission performance with a turn-on field of $0.88V/{\mu}m$ at a current density of $0.1{\mu}A/cm^2$, a threshold field of $1.98V/{\mu}m$ at a current density of $1mA/cm^2$, and a good stability of over 20 h. The filtration-taping technique is an effective way to realize low-cost, large-size, and high-performance CNT emitters.

• 한국토양비료학회지
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• 제47권6호
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• pp.598-603
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• 2014

The level of nitrous oxide ($N_2O$), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic sources, especially application of nitrogen fertilizers. Quantifying $N_2O$ emission in the agricultural field is essential to develop National inventories of greenhouse gases (GHGs) emission. The objective of this study was to develop emission factor to estimate direct $N_2O$ emission from agricultural field by measuring $N_2O$ emissions in the red pepper cultivating field from 2010 to 2012. Emission factor of $N_2O$ calculated from accumulated $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0086{\pm}0.00043kg$ $N_2O-N\;kg^{-1}$ N resulted from three year experiment of the research sites. More extensive studies need to be conducted to develop $N_2O$ emission factors for other upland crops in the various regions of Korea because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.845-848
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• 2003

We investigated a field emission property of CNTs grown on pre-treated substrates by $H_{2}$ plasma etching method in vacuum chamber (<${10^{-7}}$ Torr). To improve the emission characteristics, various catalysts and buffer layers were used. The morphology and density of catalyst layer was controlled by the different plasma pre-treatment conditions, resulting in the control of the growth characteristics of CNTs.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.786-789
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• 2007

Fabrication of dot-patterned carbon nanotube (CNT) emitters with excellent field emission properties using photo-sensitive CNT paste is described. The photosensitive CNT paste showed good photopatternability, which led us to easily form $10-{\mu}m-diameter$ dot arrays. We presented a parametric study on formulating the photo-sensitive paste and their resultant field emission characteristics.

• 한국세라믹학회지
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• 제43권11호
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• pp.743-745
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• 2006

The luminescence properties of $Sr_{1-x}Ba_xTiO_3:Pr$, Al red phosphor for Field Emission Displays (FEDs) have been investigated in powders prepared though solid-state reactions. $Sr_{1-x}Ba_xTiO_3:Pr$, Al red phosphors indicate a higher luminescent intensity, and have been found to have potential for field emission displays. The addition of Ba increased the luminescence intensity at 617 nm by up to 30%. Ba ions are effective in producing the energy transfers from host-to-activator in 4f-5d transitions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.155-156
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• 2007

Fabrication of dot-patterned carbon nanotube (CNT) emitters with excellent field emission properties using photo-sensitive CNT paste is described. The photosensitive CNT paste showed good photo-patternability, which led us to easily form $10-{\mu}m$-diameter dot arrays. We presented a parametric study on formulating the photo-sensitive paste and their resultant field emission characteristics.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.43-48
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• 1999

Using microwave plasma-enhanced chemical vapor deposition, diamond films were successfully grown on Ti-coated glass substrates at temperatures as low as around 500$^{\circ}C$ in behalf of practical applications to field emitters. Electron emission was observed at turn-on fields below 18V-$\mu\textrm{m}$. Field emission characteristics of diamond films were discussed in terms of their crystalline qualities. diamond films with poorer crystalline qualities showed better field emission properties.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.66.2-66.2
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• 2011

A polymer-based multi-walled carbon nanotube (MWCNT) field emission device was fabricated from a composite dispersion of MWCNTs and waterborne polymethyl methacrylate (PMMA). The waterborne PMMA synthesized through the emulsion polymerization method was added to minimize the reagglomeration of dispersed MWCNTs with surfactants in water, and increase the adhesion between the and the substrate. The field emission properties of the fabricated device were optimized by adjusting the density of the emitter and the adhesion between the MWCNTs and the substrate. These were done by controlling the polymer concentration added to the MWCNT dispersion, as well as the amount of spray coating on the substrate. The results confirm the successful fabrication of a polymer-based MWCNT field emission device with a low field of 1.07 $V/{\mu}m$ and a good electric field enhancement factor of 2445. The device was fabricated by adding 0.8 mg/mL of polymer solution to the MWCNT dispersion and applying 20 cycles of spray coating. Application of this same MWCNT/polymer composite solution to a flexible polymer substrate also resulted in the successful fabrication of an electric field emission device with uniform emission and long time stability.