Multiscale Modeling of Field Emission Properties of Carbon-Nanotube-Based Fibers

Abstract In the previous chapter, building on recent efforts to characterize carbon nanotube fibers (CNFs) as efficient electron emission sources suitable for compact, high-power, high-frequency vacuum electronic devices, an exhaustive approach toward optimizing CNF field electron emission (FE) properties was proposed. It consists of a platform of scientific enquiry geared toward a meaningful comparison between different CNF-based emitters. The platform envisages an iterative procedure involving (a) the growth, processing, and functionalization of CNFs; (b) full investigation of the CNF material properties before and after FE diagnosis; and (c) multiscale modeling of FE properties, including self-heating, shielding effects and beam characteristics for both CNFs, and emitting carbon nanotubes (CNTs) at the fiber apexes. The modeling would be applicable to a wide variety of CNFs and wirelike sources and would provide essential feedback to the growth, processing, and functionalization of CNFs, in order to optimize their FE properties, especially long-term stability, low noise and maximum emission current, current density, emittance, and brightness.