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%͒.

Carbon nanotubes (CNTs) have been investigated as an emitter for field emission display (FED). In our FED fabrication process, the printed CNTs are raised by a laser irradiation for the purpose to improve the emission characteristics. Because the emitters have to be controlled in each pixel individually on FED, the uniformity of the emission characteristics is necessary. We could improve the emission characteristics uniformity successfully by two methods. In the first method, the distribution of CNT raisings was homogenized by the modification of the irradiation pattern that consisted of an array of small areas. The emission deviation was improved to approximately half by the method. In the second method, the impurities of CNT raisings were cleaned by post-laser-irradiation of which fluence was lower than that of first irradiation. The emission characteristics improved and the turn-on electric field reduced from 2.1 to 1.4V∕μm. The emission deviation also improved to approximately half.

Recently the direct growth of carbon nanotubes (CNT) on glass substrates by thermal chemical-vapor deposition at low temperatures has been researched for the fabrication of field-emission displays. We have achieved synthesis of CNT on soda lime glass with a catalyst: FeZrN at low temperature (500–550 °C). The FeZrN film deposited by sputtering is amorphous. However, this film changes into a crystalloid to separate out Fe fine particles by thermal treatment. This characteristic has been successfully applied to make the precursor of CNT. There is a possibility that the density and diameter of CNT can be controlled by varying the composition ratio of FeZrN. The emission from CNT has also been obtained. The turn-on electric field has been ∼2.5–3 V/μm. We have fabricated a microtriode structure and the emission has been also recognized.

A heat‐resistant paste has been developed to solve the problem of carbon‐nanotube (CNT) loss in the heat treatment process after the printing. This paste contains a new glass powder for reductive reaction for CNT. The microscopic observation clarifies the number of CNTs in the new cathode are significantly more than the conventional cathode. The emission distribution measurements show the number of emission sites is 20 percent more than the conventional cathode. The luminance uniformity of new cathode has been significantly improved.

A new method of fabricating CNT emitter array using polymer insulator with low outgassing has been developed. A dry etching process without the damage on the CNT has been found and it proved to decrease the turn-on voltage. Better emission properties than conventional insulator has been obtained.