Recent Progress on ZnO Nanowires Cold Cathode and Its Applications

Abstract

A cold cathode has many applications in high frequency and high power electronic devices, X-ray source, vacuum microelectronic devices and vacuum nanoelectronic devices. After decades of exploration on the cold cathode materials, ZnO nanowire has been regarded as one of the most promising candidates, in particular for large area field emitter arrays (FEAs). Numerous works on the fundamental field emission properties of ZnO nanowire, as well as demonstrations of varieties of large area vacuum microelectronic applications, have been reported. Moreover, techniques such as modifying the geometrical structure, surface decoration and element doping were also proposed for optimizing the field emissions. This paper aims to provide a comprehensive review on recent progress on the ZnO nanowire cold cathode and its applications. We will begin with a brief introduction on the synthesis methods and discuss their advantages/disadvantages for cold cathode applications. After that, the field emission properties, mechanism and optimization will be introduced in detail. Then, the development for applications of large-area ZnO nanowire FEAs will also be covered. Finally, some future perspectives are provided.

Modeling the Temporal Response of Gated ZnO Nanowire Field Emitter by Considering the Charging and Self-Heating Effect for Improving the Response Speed

“…Field emitter array has important applications in field emission display [1][2][3][4][5], parallel electron-beam lithography [6][7][8][9], and X-ray source [10][11][12][13][14][15]. Until now, only CNT [16], Si nanotip [17], and ZnO nanowire [18] have been active in studies of field emitter array applications. Among them, ZnO nanowire has advantages in terms of its simple synthesis method, low cost, high uniformity, and compatibility with microfabrication techniques, which makes it outstanding in large-area gated field emitter arrays [18].…”

“…Until now, only CNT [16], Si nanotip [17], and ZnO nanowire [18] have been active in studies of field emitter array applications. Among them, ZnO nanowire has advantages in terms of its simple synthesis method, low cost, high uniformity, and compatibility with microfabrication techniques, which makes it outstanding in large-area gated field emitter arrays [18]. One of the key problems in its commercialization is how to further improve response speed, which is important for realizing the addressing or fast imaging function in a flat-panel X-ray source with desirable frequency.…”

Simulation study of a novel ZnO nanowire cold cathode flat-panel x-ray source using EGSnrc for Talbot-Lau type grating interferometry

“…In addition, compared with thermionic cathode X-ray tubes, cold-cathode flat-panel sources have unique and intrinsic advantages, such as quick temporal response, low-power consumption, etc. Large area size of flat panel sources can generate X-ray photons with high flux and addressability may provide new possibilities for X ray imaging [8][9][10]. Based on this source, we further proposed a novel flat panel X-ray source that has the potential to be used in GI.…”

Optimizing Performance of Coaxis Planar-Gated ZnO Nanowire Field-Emitter Arrays by Tuning Pixel Density

“…Gated ZnO nanowire FEAs have been fabricated and proven to be capable of emission current modulation and addressability [ 18 , 19 , 20 , 21 ]. The feasibility of using ZnO nanowire FEAs in large-area vacuum microelectronic devices has also been verified [ 22 ].…”