Advances in the Understanding of the P-N Junction Triode

During the past ten years the junction triode has been studied extensively in attempts to improve the understanding of the device. The resulting increase in understanding has made possible improvements in both device design and in transistor-circuit design. Highlights of these studies including references to approximately 100 papers, are reviewed in this paper from the point of view of relating electrical characteristics to the physical construction of the device. First the ideal-diode model resulting from Shockley´s 1949 analysis of the junction triode is reviewed, Then the differences between experimentally observed electrical characteristics and the corresponding characteristics of the ideal model, together with their explanations presented in the literature, are described, The dc characteristics are discussed first, followed by a detailed description of the increased understanding of the small-signal parameters. Other topics reviewed briefly include the effect of non-one-dimensional current flow, and switching characteristics of the triode.