Carbon-in-Al4C3 Nanowire Superstructures for Field Emitters

As a kind of ionic (or salt-like) carbide, for Al4C3, hardly any active functions have been found except for structure material purposes. However, considering the unique characteristic features of its crystal structure, we think Al4C3 in fact might have huge potential for exhibiting active functionality on field-emission applications. Herein, we report the feasibility to approach such emitters by cleating Al4C3-based nanowire superstructures. The conductive amorphous carbon (a-C) nanolayers are embedded quasi-periodically In Al4C3 nanowire and generate essential electrical contact to the insulating Al4C3. The superstructures acting as cold electron emitters display excellent field emission performance with the turn-on field as low as 0.65-1.3 V/mu m and the threshold field down to 2.1-2.6 V/mu m. We speculate that the emission characteristics, which are ever better than carbon nanotubes, are attributed to the unique crystal structure of Al4C3 and the enhanced electrons transport in the nanowires due to the existence of a-C nanolayers. Such emitters are technologically useful, became they can be easily fabricated on large substrates, and the synthesis process is simple and broadly applicable. The findings conceptually provide new opportunities for the application of Al4C3 ceramic material in vacuum microelectronic devices.