Effect of geometry and multiple-image interactions on tunneling and I-V characteristics of metal-vacuum-metal point-contact junctions

A Green’s function formalism has been used to obtain, for the first time, the exact multiple-image interactions for a hyperboloidal-tip–planar-anode model of a metal-whisker point-contact diode. I-V characteristics, including all image interactions, have been calculated for the point-contact junction consisting of electrodes with identical metals. These are compared with results for the parallel-plane diode model with exact and appropriate forms of the image barrier. In contrast to the case of the parallel-plane diode of identical metals, rectification is predicted for the point-contact diode. Significant differences between the calculated I-V curves are found to be a consequence of the different geometries and approximations for the image interactions.