Experimental Determination of Injected Carrier Recombination Rates at Dislocations in Semiconductors

The recombination probabilities associated with lineage boundaries in germanium have been determined by measuring the ratio of injected carrier concentrations on either side of such a boundary. If one knows the linear density of dislocations in the lineage boundary, the recombination cross section for a single dislocation can be inferred. The measured cross sections correspond to cylindrical recombination areas of diameter 1.15 A for holes in $n$-type germanium and 2.8 A for electrons in $p$-type germanium. On the basis of recombination at dislocations alone, these results can be used to compute the expected lifetime as a function of dislocation density, and it is concluded from these calculations that a significant part of carrier recombination in the usual melt-grown crystals takes place at dislocations.