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

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 τin is determined as a function of the concentration N2D 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 Poc of charged dots filled with an electron and found that τin decreases as Poc increases, indicating that the inelastic scattering rate of 2DEG by charged dots is higher than that by the neutral ones.