ABSTRACT
The most commonly used method for realization is based on semiconductor heterostructures, where different semiconductors are grown on top of each other. The fundamental criterion for characterizing the dimension of an electronic system is the density of states (DOS) of the energy bands. The use of nondepleted p-type buffer layers at the interface and the surface makes it difficult to attach contacts to the n layers without getting a contact to the nondepleted p layers as well. In order to get a lifetime enhancement, we must look for mechanisms that limit the possibility of carrier recombination. The usual effect of photoconductivity is based on a change in the carrier density. This chapter derives some general trends for the influence of the background photoexcitation on the decay time constant of the photoconductive signal.
