Two-dimensional electron transport in selectively doped n-AlGaAs/InGaAs/GaAs pseudomorphic structures

The transport properties of the two-dimensional electron gas in selectively doped AlyGa1-yAs/InxGa1-xAs/GaAs pseudomorphic structures grown by molecular beam epitaxy are studied. The mobility in the temperature range from 1.7 to 300 K is reported based on the Hall effect and high-field magnetoconductance measurements. The relative strengths of various scattering mechanisms are assessed through a numerical iterative solution of the Boltzmann equation and compared with the experimental Hall mobility versus temperature data. Comparison shows that at low temperature, alloy scattering determines the low-field mobility with a suitable choice of alloy scattering potential. At room temperature, polar-optical phonon scattering is the dominant mechanism. However, alloy scattering also contributes in reducing the room-temperature mobility by approximately 20% compared to polar optical scattering alone.