Y. S. Choi

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.

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.

Photoresponse characteristics of n-ZnO/p-Si heterojunction photodiodes

We report on the photoresponse behavior of n-ZnO/p-Si photodiodes. Semiconducting n-ZnO films have been deposited on p-Si substrates at 480u200a°C using various Ar/O2 ratios, 2:1, 4:1, and 6:1, to fabricate n-ZnO/p-Si photodiodes. As a laser of 670 nm wavelength illuminated the photodiodes, a maximum responsivity of 0.286 A/W and a maximum quantum efficiency of 53% were obtained at a reverse bias of 5 V from a diode prepared with an Ar/O2 ratio of 6:1. The response time of the photodiode was as short as 35 ns as measured using pulse modulation of the illuminating laser.

Nanoelectromechanical switch with low voltage drive

The triode structure vertical carbon nanotube based nanoelectromechanical switch shows excellent low voltage drive (∼4.5u2002V), owing to its vertical gate and the narrow gap between structural elements. The insulator deposition and the selective etching process steps simplify fabrication through self-alignment. The thickness of the insulator determines the width of the gap and the etching process, used to produce the vertical gate, removes the need for a complicated lithography step. The low drive voltage increases device stability and reliability and allows the device to be deployed in a wide range of applications.

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.

39.2: The Full‐Color Video Images with Uniquely‐Gated Carbon Nano‐tube Field Emission Displays

Thick-film printing processes have been applied for preparing a carbon nanotube field emission display (c-FED), which has a strong cost advantage for large-size flat panel display. For practical display applications, two types of the gated cathode structure named the normal-gate cathode and the under-gate cathode have been developed and improved. The normal-gate and the under-gate cathode structures have the driving voltages of ±35 V and ±65 V, respectively. The 5″ c-FED panel with the normal-gate cathode and the 7″ c-FED panel with the under-gate cathode were successfully implemented and excellent full-color video images were obtained.

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.

49.1: New Concept for Improvement of White Color Balance in Hologram Back-light Units

We have improved a white color balance using multi-grating period structure in the holographic backlight units that can be applicable to mobile LCD panel where several LEDs are placed at edge of guide plate as light sources. New H-LGP is based on the characteristics of grating and its diffraction angle can be determined by specific grating period. With this idea, hologram backlight unit can realize not only lower weight and less power consumption but also higher light utilization by eliminating couple of prismatic sheets which have been widely used in conventional unit inevitably.

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.

Integration of high voltage field emission display followed by macro- and nanostructural analysis on microtip

For resolving electron beam focusing and electric field breakdown between the anode and cathode plates in a high voltage field emission display (FED), the metal mesh grids are adapted in one body with spacers. The spacer charging mechanism is modeled in the real panel domain and confirmed by experiment. We analyze the morphology and the chemical composition modifications of the microtips in the narrow vacuum gap of a 5.2 in. FED panel, and infer possible degradation mechanisms in a FED device from our experimental data. The degree of oxidation formed on the microtip surface during fabrication and device operation is studied. Gas aging method for suppressing oxidation on the microtips and stabilizing phosphor is implemented for our 5.2 in. high voltage FED.