THE EFFECT OF SCATTERING ON ELECTRON-TUNNELING MECHANISM IN DOUBLE BARRIER HETEROSTRUCTURES

By using the transfer matrix approach we exactly solve the quantum mechanical counterpart of the Langevin equation for a double barrier heterostructure (DBH) system containing scattering centers in the well, and we investigate the effect of scattering on the electron tunneling mechanism. From a model calculation, we show how the scattering affects the phase coherence of the carrier wave inside the quantum well. We consider both the elastic and inelastic collision processes in the well of the DBH. The linewidth in the tunneling transmission probability is related to: intrinsic resonant linewidth (due to the electron leaking out of the barrier), elastic collision broadening and inelastic broadening. The scattering effect also results in a peak shift. Moreover, we show that the presence of an elastic scattering center modifies the peak-to-valley ratio in the I-V characteristics: in particular we demonstrate that this ratio increases whenever a particular distribution of scattering center inside the well is present. © 1990.