COLD-CATHODE EMISSION FROM CU BROAD-AREA ELECTRODES OVERLAYED BY RESIN-ZNO COMPOSITE

Short-term temporal changes in the field electron emission characteris tics were studied. The emission regime involves metal-insulator (M-I), metal-metal-insulator (M-M-I) and metal-insulator-metal-insulator (M- I-M-I) systems. In this paper, the data presented include the initial phenomenon of 'switch-on' currents, the capability of subsequent switc hing between two or more emission spectral modes, and the non linear b ehaviour in current-voltage (I-V) characteristics. Electron energy dis tributions (of double-peaked spectrum) of two or more regular states w ith non-uniform lifetime (fraction of a second to few seconds) in each state are presented. The correlation between the distribution of the emitting sub-emission centres over the cathode surface, with each of t he temporal changes and the electron energy distribution is demonstrat ed Evidence is presented that highlights the inherently unstable natur e of the surface emission centres and means to gain stability.