Scientists envision television sets of the future hanging like paintings on most household walls. Carbon nanotubes -- a remarkable form of soot that is stronger than steel at the weight of a plastic -- has unique electronic properties that may hold the key to making flat-panel displays the monitor of the future.
In a recent issue of Applied Physics Letters, a team of researchers from the University of North Carolina and Bell Laboratories/Lucent Technologies reported the highest and most stable electron emission densities observed to date -- properties desirable for flat-panel displays and the microwave amplifiers used in Navy radar technology and communication devices.
The densities observed were significantly higher than those of existing materials such as Spindt-type diamond and silicon emitters. Emission stability is a consequence of the nanotube's sharp tip coupled with its chemical robustness in a vacuum environment. Many field emission tips degrade and become blunt over time or require special coatings to prevent them from reacting with the phosphor used in display applications. The carbon nanotubes have electron emission current density above 4 A/cm2 (Angstroms per centimeter squared) and stable and uniform emission at 20mA/cm2.
The researchers have filed for three patents on their processing methods to fabricate adherent and patterned carbon nanotube films. This research is supported by the Office of Naval Research and Bell Labs/ Lucent Technologies, which recently signed a joint agreement with UNC to develop these technologies.
Journal
Applied Physics Letters