Fabrication and field emission characteristics of a novel planar-gate electron source with patterned carbon nanotubes for backlight units

This paper describes the fabrication of backlight units (BLUs) for a liquid crystal display (LCD) based on a novel planar-gate electron source with patterned carbon nanotubes (CNTs) formed by electrophoretic deposition. The electric field distributions and electron trajectories of this triode structure are simulated according to Ansys software. The device structure is optimized by supporting numerical simulation. The field emission results show that the emission current depends strongly on the cathode-gate gap and the gate voltage. Direct observation of the luminous images on a phosphor screen reveals that the electron beams undergo a noticeable expansion along the lateral direction with increasing gate voltage, which is in good agreement with the simulation results. The luminous efficiency and luminance of the fabricated device reaches 49.1 lm/W and 5500 cd/m², respectively. All results indicate that the novel planar-gate electron source with patterned CNTs may lead to practical applications for an electron source based on a flat lamp for BLUs in LCD.