Methods were proposed for deducing deep-defect concentrations from the dependences of excess majority carrier concentrations and carrier lifetimes upon illumination intensity and injection level. The methods were based upon saturation of the excess majority carrier density with increasing illumination intensity, and upon a sudden decrease in the lifetime of majority carriers with increasing excess concentration. This took place as a result of the filling of the defect level by minority carriers. In contrast to injection-level spectroscopy, both methods made it possible to determine the density of a defect without knowing any of its parameters; such as the energy level or the recombination coefficient of electrons and holes. The methods were applied to B-doped monocrystalline Si having radiation-induced deep defects of P vacancy, O vacancy and C-O complex type. It was shown that, by using these methods, it was possible to determine the density of only those deep defects which controlled the free carrier density and lifetime and gave rise to a significant difference between the excess concentrations and lifetimes of electrons and holes. The analysis was based upon the assumption that the density of deep defects was independent of the illumination intensity, that the processes of generation-recombination via deep defects were described by Shockley-Read-Hall recombination theory and that recombination via other defects, band-to-band recombination or Auger recombination was negligible.

Methods for Determining Deep Defect Concentrations from the Dependence of Excess Carrier Density and Lifetime on Illumination Intensity. S.Z.Karazhanov: Semiconductor Science and Technology, 2001, 16[4], 276-80