Modeling and experiments on the behavior of interface recombination velocities using photoconductive decay

Model calculations of the decay rate of excess carriers in various semiconductor structures after optical excitation have been made using the modeling program PC-1D. Very good agreement is found between the carrier decay rate calculated with PC-1D and that predicted by analytical expressions for the decay of the fundamental mode when n⁺ and p⁺ junctions are absent. Effective recombination velocities at various interfaces, including the n⁺ -p, p⁺-p, and free surface, have been derived from the calculated photoconductivity decay rates for these structures. Experimental measurements of the recombination velocity using photoconductivity decay for a p⁺-p structure in both EFG and CZ silicon are in order-of-magnitude agreement with calculations. Good agreement is found for an n⁺-p structure in CZ