Clean Carbon Nanotube Field Emitters Aligned Horizontally

Abstract

Horizontally aligned carbon nanotube (CNT) field emitters, which strongly adhere to the substrate and show good field emission properties, were fabricated by electrophoresis deposition and fissure formation techniques. A thin film of CNTs was deposited on a substrate, by electrophoresis, from an aqueous mixture of CNT and detergent, and then the detergent was deposited also by electropholysis. CNTs with a clean surface were exposed in the fissures produced by firing. The field emission was increased significantly due to the additional deposition of the detergent. When the CNTs were cut by increasing the firing time, the field emission increased significantly, while their stability decreased considerably. Our method does not require any further treatment for field emission.

Field Emission of Single‐Layer Graphene Films Prepared by Electrophoretic Deposition

“…Moreover, it is worth noting that the E to value of graphene films is significantly lower than those from Spindt-type Mo emitters [33] and wide-band-gap semiconducting materials, [6,[34][35][36][37][38][39] such as nanostructured diamond films, AlN, and LiF. The E to value of graphene films is also lower than that of free-standing sub-nanometer graphite sheets (E to, 4.7 V mm À1 ) synthesized by PECVD, [19] and the E to and E thr values are well comparable to those of CNT films fabricated by EPD (E to , 1.4-3.0 V mm À1 ) [28,29,40,41] and screen-printing (E to , 2-6.4 V mm À1 ) techniques. [42] The Fowler-Nordheim (F-N) theory is the most-commonly used model for understanding the electron emission from a metal surface under a strong applied field, and it has been also widely used to investigate the electron-emission behavior of various nanostructures, such as CNTs, [3][4][5][43][44][45] nanowires, [46] and nanowalls.…”

“…It should be emphasized here that, for a similar current density, our single-layer graphene film exhibits much better emission stability than single-walled-CNT (SWCNT) and multiwalled-CNT (MWCNT) films fabricated using the spray method, [48] EPD, or combination of EPD and other techniques, [29,41] and grown by the CVD process. [28] Previous studies [4] showed that the emission degradation is a factor of 10 faster for SWCNTs than for MWCNTs, because of the single shells of SWCNTs are more sensitive to ion bombardment and irradiation, while the multiple shells of MWCNTs tend to stabilize their structure.…”

“…For example, Gao et al [28] fabricated CNT films with good microstructural homogeneity and high packing density from colloidal CNT suspensions utilizing this technique, which showed excellent electron-field-emission characteristics. By combining EPD with the fissure-formation technique, Jung et al [29] obtained horizontally aligned CNT field emitters strongly adhered to the substrate and having significantly enhanced field-emission properties.…”

Electrophoretic deposition: From traditional ceramics to nanotechnology

“…Jung et al 183,184 deposited a thin film of horizontally aligned SWCNTs from an aqueous mixture of CNT and detergent. The coating was naturally dried and then pressed on the surface to make it smooth.…”

Replication of mold for UV-nanoimprint lithography using AAO membrane

“…A transparent hard stamp of quartz glass [6] or soft elastomeric stamp (for instance PDMS) [7][8][9] is done the resin cured by UV-light exposure. However, it is of importance to fabricate the desired stamp in nanoimprint lithography process.…”