• Korean Journal of Materials Research
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• v.18 no.5
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• pp.277-282
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• 2008

The effects of the field emission property in relation to the surface morphology and adhesion force were investigated. The single-wall-nanotube-based cathode was obtained by use of an in-situ arc discharge synthesis method, a screen-printing method and a spray method. The morphologies of the formed emitter layers were very different. The emission stability and uniformity were dramatically improved by employing an in-situ arc discharge synthesis method. In this study, it was confirmed that the current stability and uniformity of the field emission of the cathode depend on the surface morphology and adhesion force of the emitters. The current stability of the field emission device was also studied through an electrical aging process by varying the current and electric field.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.852-854
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• 2003

CNT paste was fabricated by mixture of multi-walled carbon nanotubes (MWNT) powder, organic vehicles and inorganic binder. Then firing process was performed at different temperature under air and $N_{2}$ atmosphere. It was found that emission property of CNT paste was changed by firing temperature and time due to interaction between remained resins and CNT powder. We obtained good emission property from CNT paste treated at $350^{\circ}C$ for 10 min.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.859-862
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• 2003

Well-aligned multiwall carbon nanotubes (MWCNTs) were prepared at low temperature of 400 $^{\circ}C$ by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWCNTs were treated by an external rf plasma source and an ultra-violet laser in order to modify structural defect of carbon nanotube and to ablate possible contamination on carbon nanotube surface. Structural properties of carbon nanotubes were investigated by using a scanning electron microscopy (SEM), Raman spectroscopy, Fourier transformer Infrared spectroscopy (FTIR) and transmission electron microscope (TEM). In addition, the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future. Various post treatments were found to improve the field emission property of carbon nanotubes.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.691-692
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• 2009

Screen printable CNT pastes were formulated including conductive nano particles (CNPs) and their properties were investigated with an expectation of stable cold cathodes for advanced lamp application. CNT cathodes showed a turn-on field of 1~1.5V/um, a life time of ~100 hours at an emission current density of 10uA/$cm^2$ for DC-bias. Detailed analysis of measured I-V was carried out by applying Fowler-Nordheim model to trace down the origin of emission property degradation.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1270_1271
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• 2009

In this research, gallium-incorporated zinc oxide (ZnO:Ga) thin films have been used as a coating material for enhancing the field-emission property of CNT-emitters. Multi-walled CNTs were directly grown on conical-type ($250{\mu}m$ in diameter) metal-tip substrates at $700^{\circ}C$ by inductively coupled plasma-chemical vapor deposition (ICP-CVD). The pulsed laser deposition (PLD) technique was used to produce 5wt% gallium-doped ZnO (5GZO) films with very low stress. The structural properties of ZnO and 5GZO coated CNTs were characterized by Raman spectroscopy. Field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) were also used to monitor the variation in the morphology and microstructure of CNTs before and after 5GZO-coating. The measurement of the field emission characteristics showed that the emitter that coated the 5GZO (10nm) on CNTs exhibited the best performance: a maximum emission current of $325{\mu}A$, a threshold field of 2.2 V/${\mu}m$.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1224-1225
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• 2008

The results of the experiment that was conducted on the electron emission property and the long-term stability of the emission current in various carbon nanotubes (CNTs)-based field emitters with a CNT/catalyst/buffer/W-tip configuration are presented herein. CNT-based field emitters were fabricated by varying the (TiN, Al/Ni/TiN) buffer layer and the (Ni, Co) catalyst material. This study aimed to elucidate how the buffer layers and catalyst materials affect the structural properties of CNTs and the long-term stability of CNT emitters. Raman spectroscopy, field emission SEM, and high-resolution TEM were used to analyze the crystalline structure, surface morphologies, and nanostructures of all the grown CNTs. X-ray photoelectron spectroscopy (XPS) was used to monitor the chemical bonds of all the buffer layers and catalysts. Electron emission measurement and a long-term (up to 40h) stability test were carried out using a compactly designed field emission measurement system.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.658-661
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• 2002

Chemical species during growth of carbon nanotubes (CNTs) in direct current-plasma enhanced chemical vapor deposition were studied in details using $C_3H_4-NH_3$ and $CO-NH_3$ mixtures through optical emission spectroscopy (OES). In the $C_3H_4-NH_3$ system, the relative intensities of CN (388.3 nm) and CH (431.4 nm) decreased and that of $C_2$ (436 nm) increased, leading to $sp^2$-graphization into the CNT structure, leading to improvement of field emission property of CNTs. In the $CO-NH_3$ system, the trend is completely reversed. Attributing to the atomic oxygen for helping the graphitization of carbon, CNTs could be grown under the flow rate of CO (180 sccm)-$NH_3$ (10 sccm). Through these results, we suggest the growth mechanism in our system.

• Korean Journal of Materials Research
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• v.14 no.8
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• pp.542-546
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• 2004

We report a new fabrication process for high performance triode type CNT field emitters and their superior electrical properties. The CNT-based triode-type field emitter structure was fabricated by the conventional semiconductor processes. The keys of the fabrication process are spin-on-glass coating and trim-and-leveling of the carbon nanotubes grown in trench structures by employing a chemical mechanical polishing process. They lead to strong adhesion and a uniform distance from the carbon nanotube tips to the electrode. The measured emission property of the arrays showed a remarkably uniform and high current density. The gate leakage current could be remarkably reduced by coating of thin $SiO_{2}$ insulating layer over the gate metal. The field enhancement factor(${\beta}$) and emission area(${\alpha}$) were calculated from the F-N plot. This process can be applicable to fabrication of high power CNT vacuum transistors with good electrical performance.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.145-145
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• 2002

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.68-68
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• 2001