Lifecycle studies of field emission of BN thin films

Amorphous BN films were prepared by the RF magnetron sputtering method and their field emission behaviors were characterized by I-V curves and F-N plots. Changes of electric field were carried out by increase/decrease in order to test the lifetime of the cascade material. In the meantime AFM and SEM monitored the change in the films' morphologies and compositions. We find that the nano-sized islands can act as the FE emitters and essentially determine the FE performance of the films. We also report the existence of an activation process, after which the cascade performs more satisfactorily in higher emission current. It is also supposed that the field-induced evaporation plays an important role in the exhaust of the cascade material.