• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권1호
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• pp.59-63
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• 2000

For the Mo-tip field emitter array, the method by which the geometrical structure of the gate insulator wall could be modified in order to improve field emission properties(turn-on voltage and gate leakage current). The device having a gate insulator of complex shape, which means the combined geometrical structure with round shape made by wet etching and vertical shape made by dry etching processes, was fabricated and the field emission properties of the three kinds of devices were compared. As a result, the electric field applied to tip apex could be increased and gate leakage current could be decreased by employing the gate insulator having geometrical wall structure of mixed shape. Finally, the obtained empirical results were analyzed by simulation of electric field distribution at/near the tip apex and gate insulator using SNU-FEAT simulator.

• 대한금속재료학회지
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• 제48권2호
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• pp.180-186
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• 2010

For the application of field emission display (FED), it is essential to develop a carbon nanotube (CNT) cathode with high emission current density. In this study, we developed and demonstrated a post-heat treatment (PHT) process to improve field emission properties of CNT cathodes. Since the PHT is intended to burn out organic materials covering the CNTs, the PHT was carried out by heating samples at a high temperature in an atmosphere. The PHT process is applied for samples processed by surface treatment with an adhesive tape. Compared to samples prior to the PHT, samples after the PHT at $360^{\circ}C$ showed about 17% improvement in emission current density. The major reason for the increased current density is mainly the increased aspect ratio of the CNTs because of the removal of the adhesive organic residues covering the CNTs, which were attached on the CNT surfaces during the surface treatment using the adhesive taping method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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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/${\mu}m$.

• 반도체디스플레이기술학회지
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• 제20권3호
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• pp.11-17
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• 2021

I performed a semi-analytical numerical analysis of the effects of core size and electric field intensity on the light emission wavelength of CdSe/ZnS quantum dots (QDs). The analysis used a quantum mechanical approach; I solved the Schrödinger equation describing the electron-hole pairs of QDs. The numerical solutions are described using a basis set composed of the eigenstates of the Schrödinger equation; they are thus equivalent to analytical solutions. This semi-analytical numerical method made it simple and reliable to evaluate the dependency of QD characteristics on the QD core size and electric field intensity. As the QD core diameter changed from 9.9 to 2.5 nm, the light emission wavelength of CdSe core-only QDs varied from 262.9 to 643.8 nm, and that of CdSe/ZnS core/shell QDs from 279.9 to 697.2 nm. On application of an electric field of 8 × 10⁵ V/cm, the emission wavelengths of green-emitting CdSe and CdSe/ZnS QDs increased by 7.7 and 3.8 nm, respectively. This semi-analytical numerical analysis will aid the choice of QD size and material, and promote the development of improved QD light-emitting devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.466-466
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• 2011

There have been several methods to fabricate carbon nanotube (CNT) emitters, which include as-grown, spraying, screen-printing, electrophoresis and bonding methods. Unfortunately, these techniques generally suffer from two main problems. One is a weak mechanical adhesion between CNTs and the cathode. The as-grown, spraying and electrophoresis methods show a weak mechanical adhesion between CNTs and the cathodes, which induces CNT emitters pulled out under a high electric field. The other is a severe degradation of the CNT tip due to organic binders used in the fabrication process. The screen-printing method which is widely used to fabricate CNT emitters generally shows a critical degradation of CNT emitters caused by the organic binder. Such kinds of problems induce a short lifetime of the CNT field emitters which may limit their practical applications. Therefore, a robust CNT emitter which has the strong mechanical adhesion and no degradation is still a great challenge. Here, we introduce a simple and effective technique for fabrication of CNT field emitter, namely filtration-taping-transfer method. The CNT emitters fabricated by the filtration-taping-transfer method show the low turn-on electric fields, the high emission current, good uniformity and good stability. The enhanced emission performance of the CNT emitters is mainly attributed to high emission sites on the emitter area, and to good ohmic contact and strong mechanical adhesion between the emitters and cathodes. The CNT emitters using a simple and effective fabrication method can be applied for various field emission applications such as field emission displays, lamps, e-beam sources, and x-ray sources. The detail fabrication process will be covered at the poster.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1591-1593
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• 2008

The tubular field emission lamp (FEL) was developed using a wire type carbon-nano-structure emitter called CNX The luminous efficiency of the tubular FEL (diode type, diameter: ${\varphi}15.5mm$, length: 200mm) has already achieved around 45lm/W and we expect to achieve over 60lm/W within the year.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.371-375
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• 2002

Emissions of thermionic cathodes and field emitters were studied using a cathode emission profiler which works based on the anode scanning method. Findings about impregnated cathodes in thermal activation and gas poisoning processes are shown. Effects of surface treatments for field emitters are studied from the viewpoint of emission profiles and characteristics of the emitters.

• 마이크로전자및패키징학회지
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• 제4권2호
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• pp.17-24
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• 1997

Spacer가 없는 Field Emission Display 정보표시소자의 진공 패키징시 패널 유리 두 께에 따른 패널 유리가 받는 응력과 패널의 중앙 부위에서의 변위를 계산하였다. 판의 각 모서리가 고정된 상태에서 일정한 압력을 받는 경우의 bending moment로부터 우리가 받는 압력을 계산하였으며 3.7"와 5.7"크기의 두가지 경우를 실험하여 계산값과 파괴양상 및 중앙 에서의 변위를 비교하였다.변위를 비교하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.764-767
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• 2007

We investigated the field emission of single carbon nanotube including the anode effect by calculating the tunneling probability of an electron. The experimental results from this study were in agreement with our theoretical calculations. The constant enhancement factor was calculated using an approximation of the potential barrier.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1277-1281
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• 2007

A Nano-tip as a cold field emitter for inducing a field emission current has manufactured in many ways. In the paper, the electrochemical etching method is used. Thus, in order to optimize the final shape as the field emitter, the reliable fabrication system for electrochemical etching was constructed. In addition, the effective parameters such as applied voltage, submerged length, meniscus height, electrolyte concentration and environmental condition(vibration, humidity, cut-off time) have investigated in detail. By controlling the parameters, reliable tungsten tip for field emitter was fabricated. And the fabricated tungsten tip was evaluated optically. Finally, the very sharp apex of the tungsten tip was observed with scanning electron microscope.