Relationship between field-emission characteristics and defects measured by Raman scattering in carbonnanotube cathodes treated by plasma and laser Improvement of emission characteristics uniformity of carbon nanotube field emission display by surface treatment J.Recently, field emission displays using printed carbon nanotubes ͑CNTs͒ as an emitter have been researched eagerly. By laser irradiation, some CNTs in the printed CNT layer stand out, and they work as the emission sites. We found that the higher CNTs that are easier to be the emission sites tend to exist at the boundary of the laser irradiation pattern. We used the irradiation patterns that consist of the arrays of microirradiation pattern to increase the total length of boundary. Both emission characteristics and emission uniformity were improved by the increase of the boundary length. We examined several lasers, and the irradiation by the second harmonic generation yttrium aluminum garnet laser of which wavelength was greatest in our experiment provided the best emission characteristics ͑turn-on electric field Ͻ2 V/m͒ and emission uniformity ͑turn-on electric field deviation Ͻ5%͒.

This article reports the fabrication process of a carbon-nanotube (CNT) field-emitter array with the silicon-ladder polymer insulator polyphenylsilsesquioxane (PPSQ), whose feature is heat resistance, high breakdown voltage, and low outgassing. CNT islands are formed with a screen-printing method, polymer-insulator coating is carried out (8 μm in thickness), and the gate electrodes are deposited, followed by patterning of the electrodes. PPSQ insulator is applied reactive ion etching (RIE) to reveal CNT emitters. Because of using mixed gases of CF4 and O2, the etching rate for CNT is half that for PPSQ, there is a margin to stop etching with enough CNT left. After reactive ion etching, emission-current density from the revealed CNT is degraded, so laser activation treatment is applied and the emission current density is boosted by a hundredfold. In the case of the triode mode, the laser condition was chosen to prevent gate damage and to improve emission characteristics. Current density of 3 mA/cm2 is obtained at the driving voltage of 35 V.

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Image flicker will cause the degradation of image quality of liquid crystal display. In this paper, the image flicker of polymer‐sustained‐alignment liquid crystal display panel is studied experimentally. We found that optimizing Vcom voltage can reduce image flicker. In addition, image flicker is sensitive to the low‐level gate voltage Vgl and high‐level gate voltage Vgh. Vgl and Vgh should be carefully optimized to minimize image flicker. Voltage holding ratio is affected by TFT’s leakage current Ioff(TFT), liquid crystal’s leakage current Ioff(lc), and circuit’s capacitance. A high resistivity liquid crystal material and high off‐state resistance of TFT should be applied to improve voltage holding ratio and reduce image flicker. Light leakage is another important factor affecting image flicker. By optimizing the shape of gate to shade the TFT channel, the image flicker can be reduced.