Electron Transport in Modulation-Doped InAlAs/InGaAs/InAlAs and AlGaAs/InGaAs/AlGaAs Heterostructures

Abstract

The possibilities of enhancing the electron mobility and high-field drift velocity in channels of modulation-doped InAlAs/InGaAs and AlGaAs/InGaAs quantum wells by tuning interaction of electrons with interface phonons are tested and reviewed. A large increase in the mobility is achieved in a novel metamorphic In0.7Al0.3As/In0.8Ga0.2As structure with the high InAs content in the InAlAs barrier layer as well as in the AlxGa1-xAs/In0.2Ga0.8As structure with the low AlAs content in the AlGaAs barrier layer. An enhancement in the electron mobility by inserting thin InAs layers into the In0.52Al0.48As/In0.53Ga0.47As quantum well is obtained. The electron drift velocity saturates at high electric fields of 1.5-5 kV/cm and achieves a maximal value of 2.5. 107 cm/s in the InGaAs quantum well with the thin InAs and GaAs inserts. © lietuvos mokslu{ogonek} akademija, 2011.