Bulb-Shaped Field Emission Lamps Using Carbon Nano-Coil Cathodes

Abstract

Bulb-shaped field emission lamps (FELs) using carbon nano-coil (CNC) cathodes were fabricated and their performances were characterized. A straight steel wire grown with CNCs was placed on the symmetry axis in the bulb as the cathode. The anode was defined by a Ni film deposited on the bottom hemisphere of a 60-mm-diameter glass bulb. And a phosphor layer was coated on the Ni film for light generation via cathodoluminescence. A numerical simulation model for this geometry also was constructed. The simulated current-voltage curves agree well with the experimental results and reproduce the trends observed in the experiment. The effects of varying the length and diameter of the cathode were studied. Both experiment and simulation showed that the total field emission current increases with the cathode length and decreases with the cathode diameter. Although the design is simple and inherently low-cost, good uniformity of light emission over the entire anode was demonstrated.

Carbon nanomaterials synthesized using a spray pyrolysis method

“…In recent years, several research teams, including us, have used CNCs as the cathode material to fabricate field emission lamp (FEL) devices [26,27]. The results of these previous studies have indicated that CNC cathode materials can effectively increase the lighting uniformity and light-spot density of FELs.…”

Improvement of field-emission-lamp characteristics using nitrogen-doped carbon nanocoils

“…Compared with a CNT of the same length, a CNC has considerably more FE points [20,21]. In recent years, several research teams, including the present author's team, have used CNCs as the cathode material to fabricate FEL devices [22,23]. The results of these previous studies have indicated that CNC cathode materials can effectively increase lighting uniformity and light-spot density.…”

Fabrication and Simulation of Self-Focusing Field Emission X-ray Tubes

“…Additionally, CNCs are more robust than CNTs because the former are much thicker and thus can withstand a higher current density. Owing to their much larger diameter and higher FE site density, CNCs exhibit better long-term current emission stability, current density, FE efficiency, and lifetime than CNTs [18,19], and so they have already found application in FE lighting [38][39][40][41]. Consequently, CNCs are used as the emitter material in the X-ray tube in this work.…”