Thermionic and Semiconducting Properties of [Ag]–Cs2O, Ag, Cs

Abstract

Thermionic emission measurements have been carried out on [Ag]–Cs₂O, Ag, Cs layers in a state of near maximum thermionic yield. The data have been plotted according to the Fowler equation to determine thermionic work functions; an average value of 0.83 ev has been obtained. However, cooling the layers, below ambient, to temperatures of −40°C, results in an increase of work function of approximately 0.3 ev. Photoelectric emission measurements on these same layers yield an average photoelectric work function of 1.06 ev. Conductivity measurements on Cs₂O, Ag, Cs layers are linear between 100 and −70°C; an activation energy of ∼0.1 ev has been determined from data in this temperature range. Conductivity measurements on Cs₂O layers containing no reduced silver exhibit changes in slope similar to the thermionic data. Activation energies computed from above the break in conductivity data are ∼0.25 ev. Cooling the layers to −70°C and below results in increases of activation energy of ∼0.1 ev.