Inelastic scattering processes in GaAs/ n-AlGaAs selectively doped heterojunctions with InGaAs quantum dots

Abstract

Inelastic scattering processes of the two-dimensional electron gas (2DEG) in both normal and inverted n-AlGaAs/GaAs heterojunction FET structures have been studied, for the case where InGaAs dots are embedded in the vicinity of GaAs channel. By analyzing the magnetoresistance data, the inelastic scattering time τ in is determined as a function of the concentration N 2D of 2D electrons and shown to be reduced by 10–40% by the presence of InGaAs dots. By investigating a GaAs/ n-AlGaAs inverted heterojunction FET with embedded InGaAs dots, we have varied the percentage P oc of charged dots filled with an electron and found that τ in decreases as P oc increases, indicating that the inelastic scattering rate of 2DEG by charged dots is higher than that by the neutral ones.