SELF-ORGANIZED STRUCTURES OF THE ELECTRONIC TRANSPORT IN SEMICONDUCTORS

The autocatalytic nature of the multiplication process for the mobile charge carriers in the low temperature avalanche breakdown regime of a semiconductor results in strongly nonlinear electronic transport behavior. As a consequence, the spontaneous generation of spatial and/or temporal structures in the electronic transport can often be observed. Because of the complexity of these self-organized structures the combination of at least three different theoretical routes - microscopic semiconductor physics, nonlinear dynamics, and the theoretical concepts for dealing with critical phenomena and phase transitions - is needed for explaining all features of the observed phenomena. In this article recent developments emphasizing the third theoretical route are described. In particular, we address the factors determining the size of a current filament, discuss the critical scaling behavior of the voltage-current characteristic as a function of the lattice temperature, and point out experimental evidence for self-organized criticality near the onset of avalanche breakdown.