Field Emission of GaN-Filled Carbon Nanotubes: High and Stable Emission Current

Abstract

Field electron emission of GaN-filled carbon nanotubes, grown by microwave plasma enhanced chemical vapor deposition, was investigated. The detailed structural characterization shows that the filled nanotube has a GaN-core/C-shell structure, in which the GaN wire corresponds to a wurtzite structure. The field emission properties of the GaN-filled carbon nanotubes have been achieved with high and stable emission current. It is attributed to the unique cable-like structure, which makes the GaN-core/C-shell composite mechanically solid and chemically stable. This study suggests the GaN-filled carbon nanotube as an ideal candidate for future high-current and high-power field emitter applications.

Filled Carbon Nanotubes: (X@CNTs)

“…An obvious enhancement to this application could arise if filling the nanotubes were to produce some obvious benefit with regard to enhancing the field emission properties. There are relatively few works describing the enhancement of such field emission apart from a brief communication by Liao et al [200] describing the stable field emission from GaN filled nanotubes (Figure 5a.17) synthesized by a combination of catalytic growth and plasma enhanced deposition [201]. A close study was carried out by Domrachev et al [202] who have also investigated the MOCVD synthesis and field emission characteristics of Ge-filled carbon nanotubes, but the containing nanotubes were made of a 'diamond-like' carbon material instead of genuine graphene-based carbon.…”

“…At least one study has also described the field emission characteristics of an array of nanotubes filled with iron oxide [203] but, as with the GaN studies, this work has concentrated on filled MWCNTs rather than filled SWCNTs presumably due to the comparative ease of synthesis and also due to the relative mechanical stability of MWCNTs compared to SWCNTs during the electron emission process. Reprinted with permission from [200].…”

Field emission characteristics of single crystal LaB6field emitters fabricated by electrochemical etching method

“…Today a large number of new materials have appeared through enormous efforts of researchers, including carbon nanotubes [2][3][4], diamond films [5][6][7], zinc oxide nanowires [8][9][10] and so on. Furthermore, lanthanum hexaboride (LaB 6 ) is also a good candidate for field emission emitters due to its low work function, low resistivity, low sputtering yield, high melting point, high chemical stability and excellent mechanical stability against ion bombardment.…”