Résumé:
This work extends the studies of the effect of the variation of the molar fraction
“ x” on the properties optoelectronics of superlattices generated by specific sequences and
disordered superlattices. We numerically studied the nature of the states of these structures
by exact airy function formalism and transfer-matrix technique. Concerning Structures
generated by specific sequences the fault of the potentiel introduced induced into the
spectrum of the transmission a fragmentation of the principal minibande in several
subminibandes separated by minigaps. The number of minigaps created equal to the
number of defects introduced. The observed phenomena are the results of destructive
interference of the electronic wave functions due to the phase difference caused by the
distance caused by the sequences of each of the series superlattice. Against the results for
the disordered structures in dimer and trimer height barriers show the presence of extended
states located in the vicinity of resonances and having a high transmission value. Indeed,
the existence of extended states
is due to the cell (Dimer / Trimer) introduced.
