D.C. Characteristics of Silicon and Germanium Point Contact Crystal Rectifiers. Part II. The Multicontact Theory

Abstract

Part I has described the d.c. current-voltage characteristics obtained for typical Si and Ge crystal rectifiers, has given a summary of the published theories of the rectifier, and has shown that none of these theories accounts for the principal features of the observed characteristics. Part II describes the multicontact theory, an extension of the diode theory, and shows that this theory does account for the behavior of the observed characteristics. There also is described a graphical treatment, based upon the multicontact theory, which may be used in the analysis of experimental characteristics. The multicontact theory assumes that the contact potential at the metal-semiconductor surface varies from spot to spot. It is shown that an exponential distribution function for contact potentials may be used to account for the observed logarithmic slopes and that the observed temperature behavior of the characteristics may be explained by assuming that the distribution function varies with temperature in a manner dependent upon the nature of the contact.