Field emission from a single carbon nanofiber at sub $100nm$ gap

The authors report the electron field emission from a single carbon nanofiber (CNF) over a range of anode to CNF tip separations of $20–5500nm$⁠. Our results show that the field enhancement factor $γ$ is associated with the electrode separation $(S)$⁠. The modified Miller equation is a reasonable empirical model to describe the behavior of $γ$⁠, which varies with $S$ over a large range of values. The $γ$ approaches to an asymptotic value of 415 or 1 when $S$ is very large or very small as compared to the length of the CNF, respectively. The maximum field emission current sustained by the single CNF without causing damage was estimated to be as high as $15μA$⁠.