Deok-Hyeon Choe

Improved emission stability of single-walled carbon nanotube field emitters by plasma treatment

We investigated the effect of plasma treatment on single-walled carbon nanotube (SWCNT) field emitters, which were fabricated by printing a photoimageable SWCNT paste, to improve emission lifetime. The treatment was performed by applying a dc pulsed voltage between two electrodes, where the cathode was the SWCNT emitter to be treated and the anode was a bare indium-doped tin oxide glass, under inert gas (Xe∕Ne) atmosphere. With increasing applied voltage and treatment time, the stability of the emission current at a constant electric field is improved, while the field to reach a required emission current becomes high. We attribute the improved emission stability to the removal of a small portion of protruding emitters, which dominate initial emission characteristics. The elimination of small number of prominent emitters allows a greater number of emitters to be active on emission with a compensation for higher electric-field application. We expect that the plasma treatment introduced in this letter will p...

Improvement of Interpixel Uniformity in Carbon Nanotube Field Emission Display by Luminance Correction Circuit

Interpixel uniformity is critical to image quality, and is hard to be improved by structural reformation of emissive elements because of nonuniformity in luminance characteristics of subpixels in self-emissive device like the carbon nanotube field emission display (CNT-FED). In this paper, we discuss the improvement of the interpixel uniformity by individually controlling the luminance of all subpixels in a display panel. We propose a prototype CNT-FED with improved interpixel uniformity using luminance correction circuitry. The analysis of interpixel uniformity with the proposed luminance correction circuit shows that the index of interpixel uniformity increases about 8% with only about 10% luminance reduction ratio that is a relatively small penalty compared to the enhancement of the interpixel uniformity. The proposed correction method can also be used to ensure improvement of the interpixel uniformity in large-size CNT-FED panels.

Flat Panel Display Using Carbon Nanotube

We fabricated 15 inch diagonal field emission display with a double-gated structure in which the carbon nanotube was used as electron emission sources. The resolution, operation voltage, brightness, and color gamut were almost reached the values of the user demand. The lifetime and pixel-to-pixel uniformity are remained to be improved. The backlight unit of LCD was also demonstrated with carbon nanotube field emission flat lamp. The cost competition and the enhanced power efficiency are challenges to be overcome for the mass production.

Long lifetime of field emitters fabricated using carbon nanotube paste

We have measured electron emission from carbon nanotube (CNT) emitter prepared using CNT paste and obtained long-term stability of field emission. Its lifetime observed in the sealed device at constant applied voltage was longer than 20,000 hrs. CNT emitter was treated by plasma in order to increase the stability. We observed that plasma treatment changed the surface morphology in CNT layer. The plasma etched the protruded CNT, resulting in the uniform height of CNT on the emitter layer.