| Abstract: | The lifetimes of excitons bound to different shallow impurities in silicon have been measured. A comparison with a theoretical calculation shows that a 3-particle Auger process dominates the recombination. In the case of high carrier concentration the lifetime of free carriers is also governed by the Auger recombination. In contrast to the bound excitons this Auger process cannot be of first order but an additional excitation, probably a phonon, must be involved. It turns out, indeed, that the excitonic Auger recombination is more “effective” than the band-to-band transition, as expected for a lower order process. A comparison of the results for the highly doped material with those for highly excited pure samples (electron-hole drops, EHD) shows that also in this case the Auger recombination dominates. |
