Indirekte Band-Band-Stoßrekombination in Germanium

Photoemission from Ge, caused by carrier injection via ap-n-junction was observed at a wavelength about 1 μm at room temperature. The dependence on energy, temperature and carrier density shows, that there appears a high energy tail of a radiative band to band recombination, which cannot be the tail of the usual radiative recombination in Ge. The intensity of the photoemission is proportional ton ² p ². The experimental results are explained as follows: Via indirect band to band Auger-recombination a hole is brought into the split-off band. In this band, the hole reaches thermal equilibrium with the lattice. While it remains in this band, it is able to recombine radiatively with electrons of the conduction band.