doi:10.1038/nindia.2016.55 Published online 25 April 2016
Researchers have synthesized vertically aligned carbon nanocups that exhibit field-emission properties when exposed to low-intensity electric fields, making them potentially useful for developing field emitters for applications in vacuum nanoelectronics1.
Field-electron emission is a form of quantum-mechanical tunnelling in which electrons pass through a barrier in the presence of an electric field. This tunnelling strongly depends on the shape and structure of the field-emitting material. However, current techniques are not suitable for making efficient field emitters.
To make efficient field emitters, the researchers synthesized vertically stacked carbon nanocups using carbon nanotubes on porous aluminium oxide nanotemplates. They then explored the field-emission properties of the nanocups by exposing them to low-intensity electric fields.
The nanocups showed uniform emission during the first six cycles. Such emission properties can be attributed to the hollow tubular structure of the nanocups, which had chemically modifiable inner surfaces and edges.
The average current emitted by the nanocups remained constant throughout the experiments and showed no signs of disruption, suggesting that the nanocups are mechanically robust against ion bombardment and field-induced stress.
“Besides potential applications in nanoelectronics, the nanocups are also suitable for making adsorbents and gas storage components,” says Bipin Kumar Gupta, the lead author of the study.
1. Gupta, B. K. et al. Field emission properties of highly ordered low aspect ratio carbon nanocup arrays. RSC Adv. 6, 9932–9939 (2016)