Highly Crystalline Single-Walled Carbon Nanotube Field Emitters: Energy-Loss-Free High Current Output and Long Durability with High Power

Power consumption reduction and energy savings for field-emission (FE) electron sources for the loading of high current output, long durability, and high power are considerably challenging in the field of materials. Here we show a new approach using a simple structure comprising highly crystalline single-walled carbon nanotubes (SWCNTs) in the cathode for meeting these goals of power consumption and energy efficiency. Efficacy and applicability were successfully demonstrated by revealing the ideal FE properties of SWCNTs via the control of their crystallinity. The FE fluctuation and emission lifetime of highly crystalline SWCNTs exhibited good stability for greater than 1300 h at 30 mA/cm2 and durability with an FE high current density of 10 A/cm2 via the application of a direct current constant voltage in the cathodic planar field emitter. Moreover, field emitters using highly crystalline SWCNTs permitted the use of new vacuum power switches for the loading power operation of greater than 27 kW, with a high loading current without energy loss and a cooling system. Highly crystalline SWCNTs as a flat plane-emission device can serve as a technological breakthrough for realizing energy savings and a low-carbon society in daily life.