Enhanced electron emission from functionalized carbon nanotubes with a barium strontium oxide coating produced by magnetron sputtering

Effect of substrate heating and microwave attenuation on the catalyst free growth and field emission of carbon nanotubes

“…Due to their excellent electron emission properties CNTs have a strong potential application as a cold cathode [6][7][8]. In order to enhance its field emission behavior, a variety of methods have been explored for surface modification of CNTs by various approaches [9] like doping with transition elements or coating of CNT-emitters with a lower work function material and nano-particles [10][11][12].…”

Improved field emission from indium decorated multi-walled carbon nanotubes

“…There are reports pertaining to decoration of CNTs with various low work function materials in the nanoparticle form such as Cs , LaB 6 , Hf, BaSrO, SrTiO 3 , CeB 6 , Ta etc. Also, some wide band gap materials like SiO 2 and MgO were deposited using different coating techniques like sputtering, spin coating, thermal evaporation, and pulsed laser deposition (PLD) [22][23][24][25][26][27][28][29]. Enhanced field emission from CNTs after plasma treatment [30], low energy ion bombardment [31], high temperature annealing [32], electrical treatment [33] and CNT carpet were also reported [34].…”

Outstanding field emission properties of wet-processed titanium dioxide coated carbon nanotube based field emission devices

“…[15][16][17] On the other hand, composite CNT cathodes by doping or attaching CNTs with metal nanoparticles or metal oxide thin films have been demonstrated to greatly improve the FE performance. [18][19][20][21][22][23][24][25][26][27][28] However, metal nanoparticles doped CNTs generally possess weak electron emission stability due to the chemical activity and poor oxygen resistance of metal nanoparticles. For example, Sridhar et al reported an ultralow turn on field (E to , defined as the required electric field corresponding to emission current density of 10 lA cm À2 ) and threshold field (E th , defined as the required electric field corresponding to emission current density of 1 mA cm À2 ) of 0.13 and 0.14 V lm À1 by decorating vertically aligned CNTs with Al nanoparticles, 20 yet, the stability of the decorated CNT composite still needed improvement as it already decreased over 10% in 1 h under a low bias stress of 0.15 V lm À1 .…”

“…28 However, the composite film still possessed a high E to of 0.8 V lm À1 (at 1 lA cm À2 ) maybe due to the poor electronic conductivity in the presence of the coated metal oxide layer. In addition, some composite films were deposited using the sputtering method, 17,18,23,27 which may give the plasma damage on the CNT surface, resulting in weak adhesion between the CNT film and the substrate, and generate poor emission stability. 29 In this letter, we reported a deposition of TiO 2 gel on the surface of screen-printed CNT films by a simple wet process to form CNT/TiO 2 composite films as an alternative choice for electron emitters.…”