24.2: Fundamental Characteristics of Carbon-Nanotube Lighting Tubes Used for Large-Scale Tiled Display

In this paper, cathodes and gate electrodes structure of a CNT tube and its fundamental characteristics such as brightness, drive voltage vs emission current, adjacent leakage of light and emission life are described. The brightness of 3000 cd/m2 was obtained with a 10 kV anode voltage and a 0.5 mA anode current. The CNT cathode was made by printing to achieve low costs, and its thickness was approximately 10 μm. The gaps between the bare cathodes glass and the gate electrodes were about 50 μm, therefore, the gaps between the CNT cathodes and the gate electrodes were 40 μm. An emission current up to 2.5 mA was extracted by applying pulse voltage of 200-300V to the gate electrode and about 20% reached the anode to excite the phosphor. The variation in electron emissions was measured over 6000 hours, and it was found that a sharp decrease of the emission current occurred at an early stage of the test and then it decreased gradually. It is very important for the successful manufacturing of the CNT tube to avoid a short circuit between the cathodes and the gate electrodes. We added some adhesive additives to the CNT paste and achieved no short circuits between them.