The carrier recombination lifetime in light-degraded B-doped Czochralski-grown wafers was measured by using quasi steady-state photoconductance methods. A very strong increase in the carrier lifetime was observed for excess carrier concentrations of between 1014 and 2 x 1016/cm3. This was attributed to BiOi defect pairs. The marked increase in the defect-related carrier lifetime permitted the determination of the previously unknown hole-capture cross-section of the BiOi pair. This value, of between 4.5 x 10-16 and 1.2 x 10-15cm2, was 2 to 3 orders of magnitude smaller than the corresponding electron-capture cross-section.

Injection-level dependence of the defect-related carrier lifetime in light-degraded boron-doped Czochralski silicon J.Schmidt, C.Berge, A.G.Aberle: Applied Physics Letters, 1998, 73[15], 2167-9