Operation of a gated field emitter using an individual carbon nanofiber cathode

We report on the operation of an integrated gated cathode device using a si ngle vertically aligned carbon nanofiber as the field emission element. Thi s device is capable of operation in a moderate vacuum for extended periods of time without experiencing a degradation of performance. Less than 1% of the total emitted current is collected by the gate electrode, indicating th at the emitted electron beam is highly collimated. As a consequence, this d evice is ideal for applications that require well-focused electron emission from a microscale structure.