Lifetime in Pulled Silicon Crystals

Lifetime data of 46 pulled silicon crystals are interpreted in terms of the Shockley-Read recombination theory. The data are consistent with the theory under the assumption of a single recombination level and a constant concentration of recombination centers, independent of the resistivity of the crystals. However, it is not possible to distinguish between two possibilities as to the location of the recombination level in the lower or the upper half of the energy gap by this type of experiment. The energy levels thus obtained are at 0.17 ev from the valence band or 0.20 ev from the conduction band in p-type silicon and at 0.22 ev from the valence band or 0.25 ev from the conduction band in n-type silicon.