Impact Ionisation and Quantum Efficiency in InSb

Transition rates for impact ionisation initiated by a) a conduction electron, b) a light hole, and c) double impact ionisation by a conduction electron are calculated using time‐dependent perturbation theory. The relative yields of secondary carriers produced by these processes, taking into account the relative numbers of primary carriers created and the loss of light holes by various transitions from the heavy hole band, are evaluated. It is shown that while process b) is a major contributor to the quantum yield along with a), it is unlikely that c) has an appreciable effect. It is also suggested that b) may provide a small contribution to electric field induced impact ionisation, particularly in p‐type material.