Specific Features of Carrier Transport in n+–n0–n+ Structures with a GaAs/AlGaAs Heterojunction at Ultrahigh Current Densities

Abstract

The current–voltage characteristics of n⁺-GaAs/n⁰-GaAs/N⁰-AlGaAs/N⁺-AlGaAs/n⁺-GaAs isotype heterostructures and n⁺-GaAs/n⁰-GaAs/n⁺-GaAs homostructures are studied. It is shown that, for a heterostructure under reverse bias providing the injection of electrons from n⁰-GaAs into N⁰-AlGaAs, the maximum operating voltage reaches a value of 48 V at a thickness of the N⁰-AlGaAs layer of 1.0 μm, and the current–voltage characteristic has no region of negative differential resistance. The operation of a homostructure is accompanied by a transition to the negative-differential-resistance region at a voltage of 10 V. Theoretical analysis in terms of the energy-balance model demonstrated that the reverse-biased isotype heterostructure has no negative-differential-resistance region because, in this case, the field domain does not collapse in contrast to what occurs in homostructures.