Complex behavior due to electron heating in superlattices exhibiting high-frequency current oscillations

Nonlinear vertical transport in semiconductor superlattices is investigated theoretically taking into account electron heating and layer width fluctua tions. Due to electron heating the local current-field characteristic displ ays an S-shaped bistable part, in addition to the N-shaped regime induced b y resonant tunneling at low fields. The layer width fluctuations can explai n the experimentally observed jumps in the time-averaged current-voltage ch aracteristic under high-frequency oscillations. (C) 1999 Elsevier Science B .V. All rights reserved.