Electrical instability against thermal injection in multibarrier heterostructures: Theoretical model and experimental data

A simplified theoretical description of electrical instability under thermal injection in multibarrier heterostructures is given in terms of internal positive feedback in each elementary unit of the hetero-object. In the simplest case, which is a sequence of equally high heterobarriers, a pair of neighboring wide- and narrow-gap layers is taken for an elementary unit. Analytical dependences of the current and voltage in the structure on the electron temperature at the injecting boundary of the heterobarrier and the respective bistable I–V characteristics are derived. A typical I–V characteristic with a clear-cut negative resistance region is demonstrated. It is taken in quasi-static electrical measurements made on 12-$\mu$m test multibarrier GaAs/AlGaAs mesas.