Nam-geol Lee

An under-gate triode structure field emission display with carbon nanotube emitters

A new triode structure for field emission displays based on carbon nanotube emitters is demonstrated. In this structure, gate electrodes are located underneath the cathode electrodes with an in-between insulating layer, a so-called under-gate type triode structure. Although the gate is on the opposite side of the anode with respect to the cathode electrodes, modulation of electron emission from the carbon nanotube emitters by the gate voltage is confirmed. The simple structure and fabrication process may lead to practical applications for the under-gate triode type structure.

22.2: The First 9-inch Carbon-Nanotube Based Field-Emission Displays for Large Area and Color Applications

The first 9-inch carbon nanotube based color field emission displays (FEDs) are integrated using a paste squeeze technique. The panel is composed of 576 × 242 lines with implementation of low voltage phosphors. The uniform and moving images are achieved only at 2 V/μm. This demonstrates a turning point of nanotube for large area and full color applications.

P‐43: A Simple Structure and Fabrication of Carbon‐Nanotube Field Emission Display

A triode structure of field emission displays based upon carbon nanotube emitters is presented. In this structure, gate electrodes are located underneath cathode electrodes with an in-between insulating layer, so called an under-gate type triode structure. The modulation of electron emission by changing gate voltages is confirmed. The advantage of simple structure and fabrication processes may lead the under-gate triode type structure to the practical applications.

20.1: Invited Paper: New Emitter Techniques for Field Emission Displays

New emitter materials for field emission displays (FEDs) have emerged and some of them faded away. Recently, carbon nanotubes have attracted much attention as a new emitter material due to their excellent field emission characteristics. We have investigated several different structures of FEDs with carbon nanotube emitters: normal gate, remote gate, and under-gate triode structures. The panels with these structures were fabricated to be a 15″ diagonal and VGA resolution. Their field emission characteristics, uniformity, and scalability are discussed in detail.

Under-Gate Triode Type Field Emission Displays with Carbon Nanotube Emitters

A new structure of triode type field emission displays based on single-walled carbon nanotube emitters is demonstrated. In this structure, gate electrodes are situated under cathode electrodes with an in-between insulating layer, so called under-gate type triode. Electron emission from the carbon nanotube emitters is modulated by changing gate voltages. A threshold voltage is approximately 70 V at the anode bias of 275 V.

The carbon-nanotube based field-emission displays for future large and full color displays

The first 9-inch carbon nanotube based color field emission displays (FEDs) are integrated using a paste squeeze technique. The panel is composed of 576/spl times/242 lines with implementation of low voltage phosphors. The uniform and moving images are achieved only at 2 V//spl mu/m. This demonstrates a turning point of nanotubes for large area and full color applications.

Development of in-situ laser vacuum annealing and sealing processes for an application to field emission displays

A laser irradiation technique is increasingly becoming one of viable candidates for in-situ and in-line packaging of field emission displays (FED) in their near-future mass production. A high power laser was used for laser annealing as well as laser sealing processes. The former is to clean field emitter arrays (FEAs) and the latter is to melt glass frit between two glass plates by an local irradiation of a laser beam along the edges of a panel. In addition, seal-capping and getter activation processes were sequentially carried out while not breaking a vacuum inside a FED panel.

Carbon nanotube cathode with low operating voltage

A cathode based on carbon nanotube has been successfully fabricated. The operation voltage of the gated cathode mainly depends on the structures adopted and also the materials used. Several cathodes are theoretically simulated, practically prepared and finally tested in a vacuum chamber. A normal-gate and an under-gate structure show about 50 V and 70 V gate operation, respectively.

P-39: Degradation Mechanism of Spindt-Type Molybdenum Field Emitter Arrays by Oxidation and Surface Chemical Modification

Oxidation and chemical modification of molybdenum micro tip surface have been investigated to understand the performance degradation mechanism of field emitter arrays(FEAs). Molybdenum FEAs could be easily oxidized due to their interaction with oxygen-containing species including O2, CO2 and H2O during cathode fabrication or thermal sealing processes of field emission displays(FEDs). During device operation, outgassing from phosphors due to electron-stimulated desorption and from other components inside a panel such as cathode, spacers, and sealant can lead to the chemical modification of the emitter surface. The oxidation and chemical modification of the emitter surface degrade the emission characteristics, resulting in the instability of an emission current, an increase of an electron extraction voltage for a given current, and lifetime reduction of the device. After the vacuum sealing and operation of the FED device, a micro tip is observed, and compared with an as-grown one by using scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Chemical composition analyses of the degraded emitter surface by nano-probed Auger electron spectroscopy(AES) suggest that molybdenum micro tip is contaminated with S, In, C, and O after the device operation, where S and In seem to originate from the dissociation of phosphors by electron bombardment.

A novel paste for carbon nanotube FED

Thick-film printing processes are mainly used for preparing a carbon nanotube FED (c-FED), which has a strong cost advantage for large-size flat panel display applications. Depending on cathode fabrication processes, photosensitive and nonphotosensitive CNT pastes are developed. As a result, brightness of 300 cd/m/sup 2/ at a duty ratio of 1/500 is easily achieved and also a paste dot pattern of 20 /spl mu/m in diameter is successfully obtained.