Simulation of resonant tunneling structures: Origin of the I-V hysteresis and plateau-like structure

Hysteresis and plateau-like behavior of the I-V curves of a double-barrier resonant tunneling structure are simulated in the negative differential res istance region. Our simulation results show that the creation of an emitter quantum well after the current passes its maximum value is the key point i n understanding the origin of the I-V plateau-like structure. It is demonst rated that the plateau-like behavior of the I-V curves is produced by the c oupling between the energy level in the emitter quantum well and that in th e main quantum well. The hysteresis is a manifestation of the above-mention ed energy level coupling, the accumulation and distribution of electrons in the emitter, and the coupling between the energy level in the quantum well and the conduction band edge or the three-dimensional continuum states in the emitter. The effects of the structural parameters on the bistability of the I-V curves of resonant tunneling devices are discussed. The creation a nd disappearance mechanism of the emitter quantum well is presented. The ef fects of device temperature on the hysteresis and plateau-like behavior of the I-V curves are obtained. These results provide the physical basis for u tilizing the plateau-like structure of I-V curves in designing resonant tun neling devices. (C) 2000 American Institute of Physics. [S0021-8979(00)0230 2-1].