Transistors

THE INVENTION of the transistor by J. Bardeen and W. H. Brattain^1–3 has given great stimulus to research on the interaction of holes and electrons in semiconductors. The techniques for investigating the behavior of holes in n-type germanium were devised in part to aid in analyzing the emitter current in transistors. The early experiments suggested that the hole flow from the emitter to the collector took place in a surface layer.^1,2 The possibility that transistors could also be produced by hole flow directly through n-type material was proposed in connection with the p-n-p transistor.⁴ Quite independently, J. N. Shive⁵ obtained evidence for hole flow through the body of n-type germanium by making a transistor with points on opposite sides of a thin germanium specimen. Such hole flow is also involved in the coaxial transistor of W. E. Kock and R. L. Wallace.⁶ Further evidence for hole injection into the body of n-type germanium under conditions of high fields was obtained by E. J. Ryder.⁷