Study of thermionic-tunnel component contribution in heterostructures of InGaAs/GaAs with a single quantum well by admittance methods

A study of InxGa1-xAs/GaAs heterostructures with single quantum well (SQW) carried out by admittance methods demonstrates two competing emission mechanisms for carriers: thermionic and tunnel. The dependence of thermionic conductance peaks on the reverse bias has resonance character. We noticed a temperature independent plateau on the conductance-temperature spectra, which is always related to the tunnel nature. We guess the observed effect is the resonant tunneling through the two-barrier potential formed at the QW borders due to doping.