Current Multiplication Processes in n-Type Germanium Point-Contact Transistors

The various theories that have been put forward to explain the high values of current gain α found for germanium type A transistors, particularly at low values of emitter current, are briefly recounted. Experiments are described which suggest strongly that the `hole trap' theory as developed by Sittner is not applicable to type A transistors. A possible explanation involving a decrease in collector barrier height by the holes arriving there is examined and is shown to account, at least qualitatively, for the increase in α at low values of emitter current.