Improvement of the emission current from a cesiated metal-oxide-semiconductor cathode

We have reduced the work function of the gate electrode of a metal-oxide-semiconductor tunneling cathode by cesiation. After cesiation, there was a considerable increase in the emission current and a large number of electrons were detected at energies lower than the original vacuum level of the poly-Si gate electrode. These results indicate that almost all the tunneling electrons have energies lower than the original vacuum level of the gate electrode, and that after cesiation electrons initially prevented from being emitted by the original vacuum level were emitted, because of the reduced work function due to cesiation.