Initiation of arc cathode emission in Cu2O films

Experiments on Cu2O films over a wide thickness range are described in which three techniques have been used: (a) photo-electron-emission measurements in vacuum (b) I/V characteristics using a metal top electrode on the film (c) surface potential-difference measurements. These results have been correlated with scanning electron-micro-scope studies of copper-arc cathode microstructure to give new data on the initiation of electron emission. Ultra-violet radiation is shown to make possible switching times as low as 1 ns by increasing the electrical conductivity of the oxide film, but the electric field across the oxide required to produce switching depends on positive ion charging.