Results of simulations for stationary and
timedependent conditions
For the numerical simulation the typical parameters of the host crystal are required. Beside the usual bulk
parameters NA,ND, epsilon ,sigman and sigmap the equilibrium value of the potential modulation Vo is needed,
too. In our case the experimental verification is done with PbTe p-n-p structures grown on BaF2 substrates. The
range of the doping level is 10^17 ... 10^18 cm^-3, epsilon approx 400, the values of the bulk conductivities are
taken from reference bulk samples. Finally the potential modulation Vo is sufficiently represented by the energy gap
(Eg approx 190 ... 230 meV) for temperatures below 77K. This assumption is based on the fact that doping is done
via resonant vacancy states for both p- and n-type-layers and that the Fermi level therefore is pinned near the
corresponding bandedges.
The general behaviour of the structures under optical excitation is very complex and many different situations are
possible for the numerical simulation as well as for the experiment. Therefore several special cases are choosen in
order to make clear the key features of these structures .
For more detailed information