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A numerical procedure based on the time-dependent Kohn-Sham equation with an improved boundary condition for the modeling double barrier resonant tunneling diode is presented. The dependence of current components on well widths in AlGaAs/GaAs/AlGaAs structure is studied. An oscillatory behavior was observed as the width of the well is changed. Our evaluation shows that this oscillation cannot attribute to the well-known oscillation at resonance state.

In this paper we present model calculations of the current-voltage characteristics for the CdTe/CdMgTe double barrier structures based on the assumption that the electron effective masses in the barrier and well regions of double barrier structure are different. The main features of the measured I-V characteristics, i.e., the small current peak at low bias and much larger peak at high voltage, are reproduced quite well by the calculated curve. The results of magnetotunneling experiments can be also understood in the frame of the proposed model.

In this paper we consider the influence of "mass barrier" and elastic scattering processes on the shape of j(V) and j(B) characteristics. Two scattering mechanisms, i.e. Coulombic on ionized impurities and on potential fluctuations in double-barrier structures are considered. The "mass barrier" shifts the whole j(V) characteristic slightly towards lower voltage and makes the resonant energy ER dependent on magnetic freld. On the other hand, both considered scattering mechanisms change the shape of j(V) and j(B) characteristics by shifting the oscillation maxima towards lower applied voltage.

The existing theory of the resonant tunneling phenomena in double-barrier structures takes into account the energy quantization in the well confined between the barriers only. In real tunneling structures there is another well, i.e., the accumulation well in the spacer region separating the highly doped region and the double-barrier structure. In the present paper the transmission coefficient for double-barrier structures with an accumulation layer as a function of applied voltage has been derived. The experimentally observed oscillations of the tunneling current can be explained b y the obtained quantization of the energy spectrum in the accumulation well. PACS numbers: 73.40.Gk

The tunneling probability through a double-barrier ZnSe/ZnTe structure is calculated using both wave-packet time dependent quantum mechanics and stationary planar-wave approximation. The obtained I-V characteristics are compared and very good consistence in resonant peaks width and position is observed. The absolute value of tunneling probability obtained in time-dependent and stationary approach is also similar.