MINORITY-CARRIER MAGNETO-OSCILLATIONS IN THE BIPOLAR QUANTUM-WELL RESONANT-TUNNELING TRANSISTOR

Magneto-oscillations due to a minority carrier two-dimensional electro n gas (2DEG) in the base of a bipolar quantum well resonant tunneling transistor at liquid helium temperatures are reported, we believe, for the first time. These are attributed to a high-density 2DEG formed in the 20 nm undoped setback layer between the base and emitter. The 2DE G density has a nonmonotonic dependence on the emitter/base junction b ias, increasing to a maximum at flatband conditions, then decreasing a t higher bias. Associated lateral electron diffusion dominates recombi nation such that the current gain can increase 1000 times in a 6 T mag netic field. (C) 1996 American Institute of Physics.