ON CURRENT AMPLIFICATION IN POINT CONTACT TRANSISTORS

For an n-type transistor, with copper and phosphor-bronze whiskers respectively for its emitter and collector, as the result of electrical forming, the emitter should have a metal-p-n structure. In the first part of this paper, the forward characteristics of such a structure is analized for the whole range of current, with special reference to the variation of the emission ratio γ with the current. The design requirement of a flat γ-Ie curve is discussed. The second part of the paper contains an analysis of current amplification of the collector. The structure assumed is a metal-p-n junction, the diffusion of phosphorus into the structure causing a high barrier for holes at the metal contact. By combining the result of the two parts, a resultant a-Ie, relation is calculated for a typical case. The main factors affecting the performance of the transistor and means of its improvement are discussed in some detail.