TUNNEL CURRENT OSCILLATIONS IN A GAAS ALAS DOUBLE-BARRIER HETEROSTRUCTURE/

A fine structure (oscillations) of the tunnel current in resonant, tun neling, double-barrier quantum heterostructures based on AlAs/GaAs/AlA s with a wide spacer layer was observed. The period of the oscillation s is close to h omega(LO)/e, where h omega(LO) is the longitudinal opt ic phonon energy in GaAs. A model is proposed to explain such a LO pho non-related oscillatory structure in the tunneling devices. According to this model, the carriers injected from the n(+) emitter lose energy gained in a strong electric field as a result of the emission of LO p honons in the accumulation layer on the emitter side or in the depleti on region adjacent to the collector barrier in the dependence on where the spacer layer is situated. (C) 1994 American Institute of Physics.