  A microscopic many-body transport approach for electronic properties of
spatially inhomogeneous systems is developed at the fully quantum-mechanical
level by means of plane wavelets second quantization representation. It is
obtained that current density is determined by the statistically averaged
microscopic polarization, dependent on the quantized positions and quantized
momenta of charge carriers. Distribution function of electrons includes
many-body effects via drift, diffusion and thermionic emission as well as
entirely quantum-mechanical tunneling through a Schottky barrier. Dependences
of the current versus voltage on the thickness of semiconductor layer, the
relaxation times in the neutral region and in the depletion layer, the width of
Schottky barrier and the mean free paths are investigated. It is established
that ideality factor is a function of applied voltage and depends on a relation
between the width of Schottky barrier and depletion layer. The value of at
which I-V characteristics acquire an ohmic nature is depended on the parameters
of semiconductors.
