DEFECT-INDUCED DYNAMICAL ELECTRIC-FIELD DOMAINS AND CURRENT OSCILLATIONS IN SUPERLATTICES

The results of numerical simulation of vertical transport in superlatt ices (SL) are presented showing that the introduction into SL of a sin gle quantum well with lower dopant concentration results in drastic ch anges in domain formation process as well as in overall current-voltag e characteristics of the SL. The study of temporal dynamics reveals th at such a defect, under appropriate total doping level, may induce dyn amical electric field domains, arising at the position of the defect a nd moving across the SL toward the anode. The motion of the dynamical domain results in specific oscillations of the total current. The effe ct is predicted to exist at the total donor concentration N-d of the o rder of or less than the space charge density forming the static domai n boundary.