Sung-Chon Park

A field-emission display with a self-focus cathode electrode

A field-emission display (5-in.) using thick-film carbon nanotube emitters is fabricated. A thick-film insulating layer and an emitter layer are employed for low-cost manufacturing and scalability to a large panel. A self-focus cathode for this display is proposed. An auxiliary electrode in contact with the cathode electrode surrounds the emitter layer at the center of gate aperture. The structure has several advantages in manufacturing. According to simulation results, this self-focus cathode structure shows excellent focusing effects in spite of its simple manufacturing process and 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.

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.

Nondestructive photoacoustic detection of exciton resonances in GaAs/AlGaAs multiple quantum well structures

We report nondestructive observations of both heavy‐hole and light‐hole excitons in the GaAs/AlGaAs multiple quantum wells (MQWs) using photoacoustic spectroscopy. The absorption spectra were measured by the gas‐microphone photoacoustic technique with a minimal volume cell and grazing incidence method. Two distinct peaks were clearly observed in the photoacoustic signal and phase spectra of the MQW at room temperature. A photoreflectance measurement for the given MQW structure revealed that two peaks originated from the heavy‐hole and light‐hole excitonic resonances.

Triode‐type field emission displays with carbon nanotube emitters

Abstract Carbon nanotube emitters, prepared by screen printing, have demonstrated a great potential towards low‐cost, large‐area field emission displays. Carbon nanotube paste, essential to the screen printing technology, was formulated to exhibit low threshold electric fields as well as an emission uniformity over a large area. Two different types of triode structures, normal gate and undergate, have been investigated, leading us to the optimal structure designing. These carbon nanotube FEDs demonstrated color separation and high brightness over 300 cd/m2 at a video‐speed operation of moving images. Our recent developments are discussed in details.

The commercial huddles of carbon nanotube devices

It has been passed over a decade since the first 5-inch diagonal carbon nanotube (CNT) field emission display was demonstrated. The most of technical issues were solved and the device showed promising performances at that time. However, it is not shown on a market as a new display device although alternative devices like OLED and PDP are on sale. Now scientists and engineers are developing new CNT based devices as like rf amplifiers, THz sources, array e-beam lithography tools, and X-ray sources. The hidden obstacles for the commercialization of CNT devices like the lack of standardization of detailed properties and inspection limitations of process steps should be carefully considered to avoid another failure. The presentation will cover unaddressed but critical huddles for CNT devices commercialization.

Development of backlight and X-ray source based on printed carbon nanotube field emitters

Fully-sealed 46-inch diagonal backlights using printed carbon nanotube field emitters have been developed. The impulse driving together with local dimming in the area as small as 1 cm2 lead to 4 ms moving picture response time with a frame rate 120 Hz and high contrast ratio over 1 000 000:1 in the LCD TV. The technical issues including device architecture and emitter performance are discussed here. In addition, recent results of X-ray source based on the carbon nanotube emitters are presented.

Alternating magnetic field crystallization of amorphous Si films

Abstract We investigate the solid phase crystallization of amorphous Si films on glass substrates under alternating magnetic field induction. The kinetics of crystallization are found to be greatly enhanced by alternating magnetic field. While complete crystallization takes heat treatment of more than 14 hours at 570 °C, it can be reduced by applying the megnetic field to 20 minutes. It is assumed that the enhancement of crystallization is associated with an electromotive force voltage generated by alternating magnetic field. This electric field applied in the amorphous Si may possibly be the reason for acceleration of the atomic mobility of crystallization through the modification of atomic potentials

Antiferroelectric liquid crystal display with high image quality

Abstract The antiferroelectric liquid crystal display (AFLCD) is a unique display that can at demonstrate a moving image perfectly the passive matrix driving scheme. We optimised driving the waveform and introduced a dual‐driving method. Also, by improving this driving method and using line inversion method, we realize the AFLC display of high image quality with 160(RGB) × 240, 32768 colors, crosstalk free and flicker free contrast ratio is greater than 60:1, and the brightness is above 200 cd/m2.