Introduction and Physical Concept

The simplest and chronologically the oldest approach to decrease carrier concentration in semiconductor photodetectors in order to suppress the Auger processes is to use solely electric fields. Inhomogeneous distribution of charge carriers, besides being a result of the application of external electric fields, may be caused by the existence of 

3 Chaige Carrier Management (Thermal Noise Engineering) 

The second type of structures are those with a gradient of chemical potential. These are various kinds of semiconductor junctions (isotype or p-n, homo- or heterojunclion, abmpt, or graded). 

Recombination zones usually represent a combination of two zones (typically on the detector surface) with a high and a low recombination rate, acting so to cause inhomogeneity of charge carrier distribution. 

The literature published until now mentions only the nonequilibrium detectors utilizing the mechanisms 2 and 3, although, analogously to equilibrium devices, larger response speeds (i.e., wider bandwidths) may be expected in nonequUibrium devices utilizing e.g. Schottky junctions. 

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