All-Carbon Nanotube-Based Flexible Field-Emission Devices: From Cathode to Anode

The fabrication of a flexible field-emission device (FED) using single-walled carbon nanotube (SWNT) network films as the conducting electrodes (anode and cathode) and thin multi-walled CNT/TEOS hybrid films as the emitters is reported. P-type doping with gold ions and passivation with tetraethylorthosilicate (TEOS) made the SWNT network film highly conductive and environmentally stable, and hence a good alternative to conventional indium tin oxide electrodes. CNT/TEOS hybrid emitters showed high current density, low turn-on field, and long-term emission stability, compared with CNT emitters; these characteristics can be attributed to the TEOS sol, acting both as a protective layer surrounding the nanotube tip, and as an adhesive layer enhancing the nanotube adhesion to the substrate. All-CNT-based flexible FEDs fabricated by this approach showed high flexibility in field emission characteristics and extremely bright electron emission patterns.