Dwell time in asymmetrical double‐barrier structures under DC bias voltage

The dwell time is analyzed in asymmetric double-barrier structures in which perfect resonance can occur when a bias voltage is applied. By taking into account the effective mass of the electron in each region, theoretical analytical expressions are derived for the tunneling transmission coefficient and the total resonance condition in the presence of a bias voltage. The bias voltage at which perfect resonance occurs is called the “resonance voltage.” The dependence of the probability density and dwell time of electrons on the resonance voltage is analyzed numerically. When the resonance voltage is increased while the resonant energy is kept constant, the dwell time is found to decrease. It is concluded that this occurs because the acceleration of the electrons is larger for a higher bias voltage, so that the probability density in the well region is smaller and the dwell time becomes shorter. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(3): 1–10, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20132